CzechSTAV 2013

Transkript

CzechSTAV 2013

Sborník příspěvků
z mezinárodní vědecké konference
CzechSTAV 2013
STAVEBNICTVÍ A PŘÍSPĚVEK VĚDY
roč. IV
21. – 25. října 2013
Hradec Králové, Česká republika
Odborné sekce konference | Conference Sessions:
Stavební procesy | Building processes
Inovace ve stavebnictví | Innovation in buildings
Risk Management, Project Management, bezpečnost práce | Risk Management, Project Management, Labour protection
Stavební materiály | Construction materials
Trendy stavebně technologické přípravy | Trends of building technology preparation
Ekonomika a vyhodnocování technologií | Economy and technology evaluation
Stavební teorie | Construction Theory
Editor, úprava, realizace | Edit, Published by:
© MAGNANIMITAS, Hradec Králové, Česká republika, 2013
Magnanimitas, Hradec Králové, 2013
ISBN 978-80-905243-8-5
Upozornění | Warning:
Všechna práva vyhrazena. Rozmnožování a šíření této publikace jakýmkoliv způsobem bez výslovného
písemného svolení vydavatele je trestné. | All rights reserved. Unauthorized duplication is a violation of
applicable laws.
Certifikovaná vědecká konference | Certificate Conference No.: 2259661314
European Textbook Track Number (ETTN): 040-13-13022-10-8
MAGNANIMITAS Assn. International and ECONFERENCE
is a signatory of Berlin declaration on Open Access
to knowledge in the sciences and humanities.
(http://oa.mpg.de/lang/en-uk/berlin-prozess/signatoren/)
Proceedings of the
International Scientific Conference on
CzechSTAV 2013
BUILDING INDUSTRY AND SCIENCE
vol. IV
October 21 – 25, 2013
Hradec Králové, The Czech Republic
C z e c h S T A V
2 0 1 3
Obsah | Table of Contents
DEVELOPMENT OF BOUNDARY LAYER IN BLWT STU IN BRATISLAVA AND COMPARISON WITH CFD
Ivana Oleksakova, Marek Magat
6
OVEROVANIE GEODETICKÝCH PRÍSTROJOV NA KONTROLU ZVISLOSTI
Ján Ježko
14
CONSTRUCTION IN OPOLSKIE VOIVODSHIP STRUCTURE: ECONOMIC SIGNIFICANCE
Mirosława Szewczyk, Rafał Parvi
27
SPATIAL AUTOCORRELATION OF INDICES OF PRODUCTION IN CONSTRUCTION IN EUROPEAN UNION
Agnieszka Tłuczak
34
AERODYNAMIC QUANTIFICATION - FACTOR INFLUENCING HEAT LOSSES CAUSED BY VENTILATION
Iveta Bullová
40
NEW APPROACHES TO CONSTRUCTION SITE DESIGNING
Mária Kozlovská, Jozef Čabala, Zuzana Struková
47
VLIV SÁLÁNÍ S OBLOHOU PŘI POSUZOVÁNÍ VĚTRANÉHO STŘEŠNÍHO PLÁŠTĚ
Sylvia Svobodová
56
FOTOGRAMETRICKÉ MERANIA PRI ZAŤAŽOVACÍCH SKÚŠKACH STAVEBNÝCH DIELCOV
Marián Marčiš, Marek Fraštia, Miroslava Chlepková
60
METHODOLOGY OF THE OPTIMAL DESIGN OF CONSTRUCTION OF TERRACED FAMILY HOUSES
Renáta Bašková, Marek Krajňák, Ján Slivka
69
PROGRESIVE DATA PROCESSING FOR BUILDING RECONSTRUCTION
Tibor Šoltés, Mária Kozlovská
78
UTILIZATION OF CONSTRUCTION WASTE IN THE IMPLEMENTATION OF BUILDINGS
Lukáš Prokopčák, Katarína Prokopčáková
84
TYPOLOGY OF KNOWLEDGE TRANSFER FROM FACILITY MANAGEMENT TO CONSTRUCTION PROJECTS
Peter Podmanický, Ivan Hyben
90
INQUIRY INTO CRITICAL RISK FACTORS IN CONSTRUCTION PROJECTS
Zuzana Struková, Mária Kozlovská
95
PRÍKLADY STAVEBNÝCH TECHNOLÓGIÍ PRE BÝVANIE SOCIÁLNE VYLÚČENÝCH SPOLOČENSTIEV
Eva Jankovichová
105
INFORMATION TECHNOLOGIES AND EFFECTIVE INFORMATION FLOWS IN SELECTION OF SUB-CONTRACTORS
OF CONSTRUCTION WORKS
Tomáš Mandičák, Peter Mesároš
111
ZKUŠENOSTI S APLIKACÍ MECHANO-CHEMICKY AKTIVOVANÝCH MATERIÁLŮ PRO ÚPRAVU VLASTNOSTÍ
POPÍLKOVÝCH SMĚSÍ
Václav Mráz, Jan Suda, Jan Valentin, Miloš Faltus
118
THE TERMINOLOGY OF TRADITIONAL AND MODERN TIMBER FRAME STRUCTURES
Barbora Nečasová
126
STAVEBNICTVÍ A PŘÍSPĚVEK VĚDY | BUILDING INDUSTRY AND SCIENCE
4
C z e c h S T A V
2 0 1 3
PRŮJEZDNÁ VZDÁLENOST MOTOROVÝCH VOZIDEL OD VYHRAZENÉHO JÍZDNÍHO PRUHU PRO CYKLISTY
Jiří Drbohlav
133
UKOTVENÍ OKENNÍCH RÁMŮ NA NOSNOU KONSTRUKCI LEHKÉHO OBVODOVÉHO PLÁŠTĚ OD-001
„BOLETICKÝ PANEL“ S OHLEDEM NA TEPELNÉ NEPRAVIDELNOSTI
Pavel Liška
143
IMPLEMENTATION OF HEALTH AND SAFETY DOCUMENTATION INTO SOFTWARE FOR CONSTRUCTION
TECHNOLOGY DESIGN
Lucia Tarábková
151
STAVEBNICTVÍ A PŘÍSPĚVEK VĚDY | BUILDING INDUSTRY AND SCIENCE
5
DEVELOPMENT OF BOUNDARY LAYER IN BLWT STU IN
BRATISLAVA AND COMPARISON WITH CFD
Ivana Oleksakova, Marek Magat
Abstract
In this article are described the results from testing profile of atmospheric boundary layer in
new wind tunnel BLWT in Bratislava with emphasis on comparison of the results with
simulations in CFD (Computational fluid dynamics) software OpenFoam. The values are
compared with calculated values from EuroCode.
Key words: wind tunnel BLWT STU, CFD, atmospheric boundary layer (ABL), OpenFOAM,
1
CFD VS. EXPERIMENT
Nowadays is very common to use CFD (Computational fluid dynamics) software for solve
problem in wind engineering. In most software logarithmic profiles are already built. One
from these software is OpenFoam. For OpenFoam it is important know the command for
changing parameters of boundary layer: atmBoundaryLayer. In this article we are compering
the result of atmospheric boundary layer(ABL) from software with eurocode equation and
with testing this profile in wind tunnel.
1.1 CFD
For simulation of atmospheric boundary layer we used software OpenFoam. This
software is free, open source CFD. OpenFOAM has an extensive range of features to solve,
from complex fluid flows, chemical reactions, heat transfer, turbulence, electromagnetic etc.
This means that for modeling and calculating wind flowing we can use all difference models,
laminar of turbulence. From turbulence models we have again many choices.
• Reynolds-average simulation (RAS), sometimes known as Reynolds-averaged NavierStokes (RANS). The governing equations are solved in ensemble-averaged from,
including appropriate models for the effect of turbulence.
• Large eddy simulation (LES). Large turbulent structures in the flow are resolved by
the governing equations, while the effect of the sub-grid scales are modeled.
• Direct numerical simulation (DNS): Resolves all scales of turbulence by solving the
Navier-Stokes equations numerically without any turbulence modeling. (dnsFoam
solver)
• Detached eddy simulation (DES): Hybrid method that treats near-wall regions with a
RAS approach and the bulk flow with an LES approach.
For simulation in this article is used RAS simulation. From all RAS turbulence models for
incompressible fluids is used standard high- Re k-epsilon model.
For the k-epsilon model, Richards (1989) proposed vertical profiles for the mean wind speed
U, k- turbulent kinetic energy and rate of turbulence dissipation ε. Profile is generally
simplified by assuming a constant shear stress with height [4]. All equations are for fullydeveloped ABL profiles.
6
(1)
(2)
(3)
where κ – von Karman constant (0.4-0.42)(usualy used 0.42)
C μ - model constant of the standard k-ε model
y – height coordinate
u* ABL – atmospheric boundary layer friction velocity
Equations 1-3 are an analytical solution to the standard k-ε model. In this model we have
more constants: C e1 , C e2 , σ e , C μ . These four constants are chosen in such a way that followed
equation has to be satisfied:
(4)
At the same time are valid set of Equations 2,5,6, what is analytical solution to the same
model [4].
(5)
(6)
These equations are used for inlet profiles in CFD simulations when measured profiles of U
and k are not available.
It is important, that we have chosen k-ε model, but these equations are the same for other
types of turbulence models: RNG k- ε, realizable k- ε, SST k-ω, standard k-ω, the Spalart
Allmaras model, etc. Of course for changed parameters in different models it is needed to
change parameters in equations.
1.2 Testing ABL in wind tunnel in Bratislava
In our BLWT we developed the boundary layer above type of terrain IV. which is
made up by nope foil (nopes height about 2 cm). The main equipment used for this
experiment was Dantec´s MiniCTA (Constant Temperature Anemometry). The CTA
anemometer is an anlog instrument designed for measurement of velocity in air and is
specially suited for measurement of fast velocity fluctuations. It works on the basis of
convective heat transfer from a heated sensor to the surrounding fluid, the heat transfer being
primarily related to the fluid velocity. By using very fine wire sensors placed in the fluid and
electronics all powered by Labview, it is possible to measure velocity fluctuations of small
scales and of high frequencies. The output is an analogue voltage, which means that no
7
information is lost, and very high temporal resolution, which makes the CTA ideal for
measuring spectra [7]. The principles how can we get results of velocity of the flow is shown
on Figure 2. According to this information which is translated to a computer trough A/D
board we got suitable results programmed in a software in Labview. This software is used to
run traverse arm where the MiniCTA is fixed . We built this workspace in Labview to handle
the measurement of boundary layer in our tunnel. The first of all, we put traverse arm with
bound probe to the closest point to pitot static probe to find out the closest result of velocity of
the flow (calibration of miniCTA). We start to measure the point of calibration repeatedly
until steady velocity values. After this step we put probe to the closest distance above nopes
and start measure with automatic movement of traverse arm in vertical direction (z axis) in
denser measurement about 5mm for better accuracy, after that we start slowly enlarge the
measurement range for 10mm, 20mm, 50mm and 100mm to 700mm for 20 seconds in each
point. This process is known as traversing a cross section of the flow space. In each step the
traverse moves also in horizontal direction (x axis) in every 200 mm. Then we determined the
profile of mean velocity of the air in each step. We read the temperature and the pressure
inside the lab (nailed on the wall). We used these values to compute the mass density of air
inside the lab using the ideal gas law. There we using the sampling f (Hz) of 1000 times in
each second of the measurement for the best accuracy of results of developing the boundary
layer in the tunnel.
Fig. 1 Left: Relation between Voltage (E) and Velocity (U) as working principle of the
MiniCTA , right: Traverse arm and its shifting in BLWT STU in Bratislava
1.3 Description of solved problem
All results are making in category of terrain 4, because we need to find profile for capital
city Bratislava. It is expected that the most of testing buildings will be exactly here in
Bratislava where the most high-rise buildings are built in this time. These buildings will be
testing in wind tunnel and compared with simulations as well. The first step of using new
wind tunnel is to find profile for this category and have this same profile for simulations.
Simulation of boundary layer in OpenFoam was in real domain with real dimensions
1000x1000x500m. Testing of boundary layer in wind tunnel was in wind tunnel with height
1600mm with option to change the height of ceiling. We found out that with the barrier of
150mm in the input section of wind tunnel we can have logarithmic boundary layer of
category 4 with height about 1100m. From this information we were doing the scale for
graphs. This scale for wind tunnel results compare with real domain for analysis is 1:500. At
the end of this article is conclusion from testing of changing the ABL in different cutting lines
in domain. These lines are in 6
8
Fig.2: Dimensions of the domain and cutting lines for testing ABL profile
2
RESULTS
From comparison of all velocities we can state this these facts:
From Fig. 3 is noticed that in wind tunnel we don’t have exactly category IV. This
category will be between cat.3 and 4. We will be testing BLWT with more heights of barrier
and we will be simulating ABL with any others parameters for having exactly the same
profile as in wind tunnel. From this graph can be concluded that the simulation results and
results from wind tunnel testing are in this part of our work not exactly the same. We have to
change the height of the barrier in inlet section of the tunnel or make a changes in inlet
velocity profile in simulation software.
In OpenFOAM we can change in follows steps: - to change Uref and Href in file U and
in file Epsilon.
From Fig.2 and 4 is obvious that the profile in OpenFoam is logarithmic but no exactly
the same as Eurocode. The most important is the velocity in height about 100 m above the
terrain. We are expecting that the highest buildings in our country will be maximum about
100-150m. For this height the results are quite good and deviation is not large. As a
comparison results from experiment in wind tunnel is approximation sufficient. For every
experiment we will be changing the curve (Uref, Href) following results in wind tunnel
(possibly may change category). So the main information will be for us experiment in wind
tunnel, and logarithmic profile will be change after known information from wind tunnel.
9
Fig.3: Comparison of boundary layer profiles: Eurocode vs. wind tunnel
Fig.4: Comparison of velocity from 0 to 80m under the surface
From fig.2 is next obvious fact that domain of height 500m in simulation is enough
because from experiment is clearly that in height over 450m curve is linear. So the velocity in
this part over the surface is standing constant.
10
Fig.5: Comparison of results of velocity in Eurocode and OpenFoam 120m above the surface
2.1 Testing OpenFOAM profile in different distances in domain
In software OpenFoam was tested profile of ABL which is build in this software. We had ease
tested model inside domain and in the middle of the domain was terrain with circle ground
plan. The parapeters of the roughness height for the ABL, k s,ABL was from [4] choosen with
formula:
(7)
Results from testing of ABL function is in fig. 5. Lines 3 and 4 are totally different because
they are behind the building we design for testing model. These lines are not so important.
The main meaning have lines 1,2,5,6. Those lines are almost the same and copy each other.
Just line no.2 is little bit differing because it is exactly after gusts of the wind on the chosen
terrain of the domain. We can conclude that the simulation of the ABL with simulation in
OpenFoam give us sufficiently accurate results and we can compare reliably the results from
simulation with wind tunnel experiments.
11
Fig.6: Comparison of velocity in 6 parts of domain in different distances in axis x
3
CONCLUSION
In this article we have proved that the results from wind tunnel experiment and simulation in
software with well-chosen values of input can be compared. If we know that the input values
in simulation are the same as in wind tunnel we can start simulate real problems in wind
engineering and liken them with experiments in tunnel.
Preferences
1.
HUBOVÁ O., OLEKSAKOVA I.:. Comparison of Various Turbulence Models, 13th
international scientific conference VSU 2013. Volume 1: Proceeding. Sofia,
Bulgaria. 6.-7.6.2013 p.145-149, ISBN
2.
MAGAT M., LOBOTKA P., ŽILINSKÝ J.: Simulation of boundary layer in BLWT
in Bratislava, ATF Conference on Acoustics, Light and Thermal Physics in
Architecture and Building Structures. Book of proceedings. Leuven, Belgium 2.3.5.2013. Katholike Universiteit Leuven, 2013, p.93-98, ISBN 978-90-8649-637-2
3.
OLEKSAKOVA I.: Modelovanie prúdenia pri obtekaní valca, Juniorstav 2013,
Conference VUT Brno, 7.2.2013, ISBN 978-80-214-4670-0
4.
BLOCKEN B., STATHOPOULOS T., CARMELIET J.: CFD simulation of the
atmospheric boundary layer: wall function problems, Elsevier 2007, Pergamonelsevier science ltd., Atmospheric environment vol: 41 issue 2, p. 238-252,
ISSN:1352-2310
5.
BITSUAMLAK, G.T., STATHOPOULOS,T., BEDARD, C., Numerical evaluation
of wind flow over complex terrain: Review. Journal of Aerospace Engineering 17
(4), 2004, 135-145, ISBN (online)1943-5525
12
6.
7.
BITSUAMLAK,G., STATHOPOULOS,T., BEDARD,C.,: Effects of upstream twodimensional hills on design wind loads: A computational approach. Wind and
Structures 9(1)2004, 37-58
OLEKŠÁKOVÁ, I. – MAGÁT, M.: Modeling of 2D Circular Cylinder in Ansys by
Using Turbulence Models. The Experiment Preparation. In: New Trends in Statics
and Dynamics of Buildings, October 3 - 4, 2013, Svf STU Bratislava, pp. 157-160.
ISBN 978-80-227-4040-1.
Acknowledgements
This paper has been supported by Grand Agency VEGA of the Slovak Republic (grant. reg.
No. 1/0480/13). We would like to say thank you Mr. Ing. Milan Janak, PhD. from company
Simulacie budov s.r.o. for valuable advices and great help with using all software for CFD
simulations.
Contact information:
Ing. Ivana Oleksakova
Slovak University of Technology in Bratislava,
Department of Structural Mechanics
Radlinského 11, 86801 Bratislava
email: [email protected]
Ing. Marek Magat
Slovak University of Technology in Bratislava,
Department of Building structures
Radlinského 11, 86801 Bratislava
13
OVEROVANIE GEODETICKÝCH PRÍSTROJOV NA KONTROLU
ZVISLOSTI
THE VERIFICATION OF GEODETIC INSTRUMENTS USED FOR THE
CONTROL OF VERTICALITY
Ján Ježko
Abstrakt
K prístrojom a pomôckam ktoré sa používajú pri vytyčovaní zvislíc i pri kontrole zvislosti
patria optické prevažovacie prístroje. Optický prevažovač ako je známe je prístroj zo zvislou
zámernou priamkou, ktorej zvislú polohu zabezpečuje urovnaná libela alebo kompenzátor.
Najčastejšie používaným prístrojom na túto činnosť je u nás prístroj Zeiss PZL. Kontrolu
a testovanie optických prevažovacích prístrojov umožňuje aj jedna z noriem z oblasti
pôsobnosti medzinárodnej technickej komisie ISO/TC 172/SC 6 - Optics and optical
instruments /Geodetic and surveying instruments: STN ISO 17123-7: 2010 Optika a optické
prístroje – Postupy na testovanie geodetických prístrojov. 7. časť: Optické prevažovacie
prístroje. Príspevok predstavuje postup testovania a výsledky z porovnania dvoch optických
prevažovacích prístrojov Zeiss PZL 100.
Klíčová slova: technické normy, optický prevažovací prístroj, cieľová značka, štatistické
testovanie.
Abstract
In order to setting out a plumb line or to control the verticality, the optical plumbing
instruments are used. The optical plumbing instrument is an instrument with a vertical line of
sight, which is held vertical using a level or compensator. The most commonly used
instrument for this activity in our country is Zeiss PZL. Control and testing of the optical
plumbing instruments also allows one of the standards from the field of activity of the
international technical committee ISO/TC 172/SC 6 - Optics and optical instruments
/Geodetic and surveying Instruments: STN ISO 17123-7: 2010 Optics and optical instruments
– Field procedures for testing geodetic and surveying instruments. Part 7: Optical plumbing
instruments. This contribution deals with testing procedure and comparison of two optical
plumbing instruments Zeiss PZL 100.
Key words: Technical standards, Optical plumbing instrument, target mark, statistical testing.
1
OPTICKÉ PREVAŽOVACIE PRÍSTROJE – ZEISS PZL 100
Optický prevažovač Zeiss PZL 100 (obr. 1.1) je prístroj, ktorého zámerná os je zvislá
a zvislicu je možné vytýčiť len smerom do zenitu. Zámerný kríž optického prevažovača
pozostáva z dvojice dvoch na seba kolmých rysiek – vodorovnej a zvislej (obr. 2.2).
Vodorovná ryska je urovnávaná kompenzátorom a zvisla pomocou alidádovej libely. Nižšia
presnosť urovnania zvislej rysky spôsobuje, že pri presných prácach sa na vytyčovanie, resp.
meranie používa iba vodorovná ryska. Aby sa odstránila chyba z urovnania vodorovnej rysky
vplyvom chyby kompenzátora, vytýčenie sa vykonáva v dvoch navzájom o 180° pootočených
polohách. Polohu bodu na cieľovej značke (terči), ktorým prechádza zvislica realizovaná
optickým prevažovačom, sa určuje v štyroch polohách, vzájomne pootočených o 90°.
14
Cieľová značka je tvorená milimetrovým
rastrom s vyznačením orientácie jednotlivých
osí (obr. 1.2). Horizontáciu prevažovača
zaistíme pomocou urovnávacích skrutiek a
alidádovej libely, upevnenej na prístroji
(alidáde), v dvoch na seba kolmých smeroch
[3].
Spriemerovaním hodnôt súradníc z prvej
a druhej polohy získavame výslednú polohu
bodu (y, x) na cieľovej značke:
1
1
y = ⋅ ( y I + y II ) a x = ⋅ ( x I + x II ) . ( 1.1)
2
2
Optický prevažovač dosahuje relatívnu
presnosť
vytýčenia
zvislice
vyjadrenú
pomernou presnosťou 1 až 2 : 100 000.
Presnosť vytýčenia zvislice je priamoúmerne na
hodnote prevýšenia medzi prevažovačom
a cieľovou značkou (pri prevýšení h = 100 m je
presnosť vytýčenia 1 až 2 mm).
Obr. 1.1 Optický prevažovač Zeiss PZL
100
Presnosť takto vytýčenej zvislice môžeme vyjadriť strednou chybou vytýčenia zvislice
v smere osi „y“ alebo „x“, ktorú vypočítame podľa vzťahu [2]:
σY =
2⋅h
, resp.
100000
σX =
2⋅h
100000
(2.2)
kde h je prevýšenie medzi optickým prevažovačom a cieľovou značkou, vyjadrené
v milimetroch.
Stredná polohová chyba vytýčenia bodu, ktorým prechádza zvislica, je potom daná vzťahom
=
σP
(σ Y2 + σ X2 ) .
(2.3)
Ak uvažujeme aj presnosť centrácie prístroja nad bodom, v tom prípade bude potrebné k
celkovej strednej polohovej chybe vytýčenia bodu zahrnúť aj túto hodnotu [2, 3].
smer pohľadu
smer pohľadu
Obr. 1.2 Zámerný kríž a spôsob určenia polohy bodu optickým prevažovačom
15
2
OVEROVANIE A KONTROLA GEODETICKÝCH PRÍSTROJOV OPTICKÉ PREVAŽOVACIE PRÍSTROJE
Medzinárodnú normu ISO 17123-7 pripravila technická komisia ISO/TC 172, Optika
a optické prístroje, subkomisia SC 6, Geodetické a meracie prístroje ako súčasť ISO 17123
(pod hlavným titulom Optika a optické prístroje - Postupy na testovanie geodetických
prístrojov) pozostávajúcej z častí uvedených [2]. Táto skupina noriem bola prevzatá do
sústavy Slovenských technických noriem( STN) v roku 2010 v pôvodnej anglickej verzii
s národným predhovorom v slovenskom jazyku.
STN ISO 17123-7 špecifikuje skúšobné postupy, zamerané na určovanie a odhad presnosti
optických prevažovacích prístrojov používaných pri meraniach v stavebníctve a geodézií.
Cieľom týchto skúšok je najmä overenie vhodnosti jednotlivých prístrojov pre príslušnú úlohu
a splnenie požiadaviek iných noriem. Postupy sú určené na skúšanie prístrojov v teréne bez
potreby ďalších zariadení a sú navrhnuté tak, aby bol minimalizovaný vplyv atmosférických
podmienok na výsledok testu [4].
Štruktúra normy je zhodná pre všetky normy z tejto rady a pozostáva z nasledujúcich bodov:
•
•
•
•
•
•
•
•
•
pôsobnosť – uvádza oblasť využitia a pôsobnosti danej časti normy,
normatívne odporúčania – citácie a odkazy,
termíny a definície,
požiadavky – udáva typy prístrojov a pomôcok, metódy a dĺžky merania a pod.,
princíp testu a konfigurácia pri testovaní – uvádza stabilizáciu a rozmiestnenie
bodov, počet opakovaní (sérii) a pod.
meranie – postup merania, počet opakovaní (sérii),
výpočet – vzťahy potrebné na výpočet odchýlok a stredných chýb,
štatistické testy – testy na základe ktorých sa posudzuje spoľahlivosť a presnosť
daného prístroja
príloha – obsahuje vzorové príklady nameraných a spracovaných údajov.
2.2 Testovanie prístroja PZL podľa STN ISO 17123-7: 2010 Optika a optické prístroje –
Postupy na testovanie geodetických prístrojov. 7. časť: Optické prevažovacie prístroje
Táto norma definuje skúšobné postupy, ktoré sa používajú pri určovaní a stanovení presnosti
počas používania optických prevažovacích prístrojov pre meračské účely. Postupy uvedené
v tejto norme sa týkajú používania prístrojov v stavebnej praxi pre kontrolné a overovacie
merania a zároveň umožňujú určenie presnosti meraných údajov [4].
Požiadavky
Pred začatím merania je potrebné zabezpečiť si potrebné prístroje a pomôcky. Treba použiť
pomôcky, ktoré sú doporučené výrobcom. Do úvahy treba brať aktuálne počasie a prostredie
v ktorom budú merania realizované. Presnejšie výsledky budú získané pri laboratórnom
podmienkach, ale dôveryhodnejšie výsledky budú dosiahnuté ak sa prostredie prispôsobí
podmienkam v akých bude realizovaná plánovaná úloha.
Pri optických prevažovačoch sa ako cieľová značka používa terč na, ktorom je pripevnená
pravouhlá mriežka x – y, kde veľkosť intervalu mriežky t musí spĺňať:
h
(2.4)
Γ
kde h je prevýšenie medzi optickým prevažovačom a cieľovou značkou, vyjadrené
v metroch (prevažovaná výška), Γ je zväčšenie ďalekohľadu (u Zeiss PZL 100 je zväčšenie
31,5 násobné), 2.9 je konštantný faktor umožňujúci dobrý odhad veľkosti mriežky [4].
t ≥ 2.9 ×
16
Princíp testu
Presnosť určenia polohy bodu pri všetkých typoch optických prevažovacích prístrojoch je
priamoúmerne závislá na hodnote prevýšenia medzi prevažovačom a cieľovou značkou.
Relatívna empirická stredná chyba sISO − plumb vyjadruje presnosť, ktorá sa dosiahne pri určení
jedného bodu s príslušným prevažovaným prevýšením. Nasledujúce skúšobné postupy sa
použijú pre určenie presnosti počas používania určitou skupinou meračov s určitými
prístrojmi, kde môžu nastať tri alternatívne kombinácie:
•
jeden merač, jeden prístroj počas celého prebiehajúceho merania,
•
jeden testovaný prístroj za rôznych atmosférických podmienok,
•
dva prístroje testované za rovnakých atmosférických podmienok [4].
Konfigurácia pri testovaní
Konfigurácia pri testovaní pozostáva s optického prevažovača, cieľovej značky
reprezentovanej mriežkou x – y s intervalom delenia, ktorý má spĺňať podmienku uvedenú vo
vzťahu (2.4). Cieľová značka je umiestnená vo výške približne rovnakej ako je výška pri
plánovanej meračskej úlohe. Na obrázku 2.1 je znázornená mriežka x – y s intervalom delenia
2 mm, s číslovaním a označením osí x a y, ktoré zabráni ich zámene [4].
Obr. 2.1 Príklad mriežky x - y [2]
Meranie
Pred začatím merania je potrebné nechať prístroj aklimatizovať v prostredí, pričom
požadovaná dĺžka aklimatizácie je závislá od teplotného rozdielu medzi skladovou teplotou
prístroja a teplotou ovzdušia pri meraní. Teplotnému rozdielu 1°C sa odporúča dĺžka
aklimatizácie cca 2 minúty. Pri testovaní sa vykonávajú sa tri série meraní (m=3) kde každá
séria sa skladá s 10 opakovaní (n=10). Medzi jednotlivými sériami meraní sa poruší
horizontácia a prístroj sa opakovane horizontuje. Výsledkom merania sú dva súbory
meraných údajov jeden pre hodnoty na x-ovej osi (x j,I , x j,II ) a druhý pre hodnoty na y-ovej osi
(y j,I , y j,II ) [34].
2.3 Testovanie vybraných prístrojov Zeiss PZL 100 - realizácia
Konfigurácia pri meraní
Optický prevažovač sa využíva v geodetickej praxi vo väčšine prípadov na vytýčenie zvislice
a to buď v smere nahor prípadne nadol. Vytýčením zvislice sa kontrolujú zvislosti a náklony
stavebných objektov z ktorých je možné odvodiť vodorovné posuny pozorovaných bodov a
17
objektov. Pri realizácii takýchto meraní
sa nepoužije jeden pozorovaný bod, ale
množina
vhodne
rozmiestnených
pozorovaných bodov na danom objekte.
Preto aj pri testovaní optického
prevažovača Zeiss PZL 100 bola zvolená
za pozorovaný objekt sedem podlažná
budova, ktorej výška dosahuje 25 m. Rez
stavebným
objektom
s vyznačením
polohy pozorovaných bodov a prístroja je
obr. 2.2.
Pozorované body boli umiestnené na
medziposchodiach vo výške približne
1,80m od podesty a stabilizované
pomocou kovovej podložky, ktorá bola
pevne spojená so stenou. Podložka
zabezpečovala trvalú stabilizáciu bodu
(obr.2.3).
Pozorované body boli signalizované
dočasne a to pomocou cieľovej značky,
na ktorej je upevnená mriežka x – y
s intervalom delenia 1mm (obr. 2.3).
V tabuľke 2.1 je uvedený zoznam
pozorovaných bodov s prevažovanými
výškami h [3].
Obr. 2.2 Rez stavebným objektom s vyznačením
polohy pozorovaných bodov
a polohy prístroja
Tab. 2.1 Zoznam pozorovaných bodov s prevažovanými výškami
Pozorovaný bod
1
2
3
4
5
6
Prevažovaná výška h [m] 4.450 8.520 12.330 16.260 20.180 23.740
Obr. 2.3 Kovová podložka na upevnenie cieľovej značky (vľavo) a cieľová značka s mriežkou
x –y (pohľad zdola)
2.4 Spracovanie nameraných údajov
Na každom so šiestich bodov boli vykonané tri série meraní (m=3), kde každá séria sa skladá
s 10 opakovaní (n=10), pomocou obidvoch prístrojov [4].
18
Obr. 2.4 Znázornenie spôsobu odčítania jednotlivých polôh
Meranie každej série je hodnotené samostatne, kde rozdiely medzi x j,I a x j,II respektíve y j,I a
y j,II sú hodnoty odchýlok δx j , δy j (obr. 2.4), [4]:
1
2
δ x j =⋅ ( x j , I − x j , II )
a
1
2
δ y j =⋅ ( y j , I − y j , II ) ,
(2.5)
kde j=1, ..., 10. Ďalším krokom je výpočet kvázi – odčítaní x j a y j podľa vzťahu (2.6) :
1
1
(2.6)
x j =⋅ ( x j , I + x j , II ) a
y j =⋅ ( y j , I + y j , II ) ,
2
2
kde j=1, ..., 10, x j je stredná hodnota z meraní x j,I a x j,II , y j je stredná hodnota z meraní y j,I a
y j,II.
Priemerné hodnoty kvázi – odčítaní sú vypočítané podľa vzťahu (2.7) a stredné hodnoty
odchýlok podľa (2.8)
1 10
1 10
a =
(2.7)
=
⋅ ∑ xj
y
⋅ ∑ yj
x
10 j =1
10 j =1
1 10
⋅ ∑δ x j
δ=
x
10 j =1
a
δ=
y
1 10
⋅ ∑δ y j .
10 j =1
Z priemerných hodnôt kvázi – hodnôt sa vypočítajú opravy r x,j a r y,j
rx , j= x − x j
ry , j= y − y j .
a
(2.8)
:
(2.9)
Výsledné súčty opráv v jednotlivých osiach x a y budú mať tvar:
10
10
∑ rx2,i =∑ rx2, i, j
kde
∑r
∑r
2
x ,i
2
y ,i
∑ ry2,i =∑ ry2, i, j
a
j =1
(2.10)
j =1
je súčet štvorcov rezíduí v smere osi x,
je súčet štvorcov rezíduí v smere osi y.
Celkový súčet štvorcov rezíduí
∑r
i
2
bude mať tvar:
=
r
∑
∑r
2
i
2
x ,i
+ ∑ ry2,i .
(2.11)
19
Výpočet empirických štandardných odchýlok prenášaného bodu pre jednotlivé zložky x a y
pre danú prevažovanú výšku:
s x ,i =
∑r
2
x ,i
s y ,i =
a
v x ,i
∑r
2
y ,i
(2.12)
,
v y ,i
kde v x,i =v y,i =10-1=9 je počet stupňov voľnosti v x -ovej a y - ovej zložke. Empirickú
štandardnú odchýlku prenášaného bodu získame zo vzťahu
si =
∑r
i
vi
2
,
(2.13)
kde v i =20-2=18 je počet stupňov voľnosti (počet nadbytočných meraní) pre obe polohy.
Jednotlivé hodnoty empirických stredných odchýlok pre obidva prístroje a pre všetky sérii
meraní sú uvedené v tab. 2.2 a tab. 2.3 [3].
Tab. 2.2: Empirické štandardné odchýlky prístroja č.1
Prístroj č.1 : Zeiss PZL 100, v.č. 214 456
1
2
3
4
s [mm]
6
1
2
3
0.06
0.08
0.13
0.15
0.61
0.54
Séria
5
0.05
0.08
0.11
0.14
0.81
0.57
0.05
0.06
0.09
0.11
0.67
0.63
1
2
3
0.07
0.12
0.13
0.25
0.69
0.73
Séria
2.
meranie
1.
meranie
Č. bodu
0.07
0.14
0.13
0.27
0.84
0.79
0.07
0.13
0.10
0.21
0.74
0.74
Tab. 2.3: Empirické štandardné odchýlky prístroja č.2
1
2
3
s [mm]
Séria
Séria
2. meranie 1. meranie
Č. bodu
4
5
6
0.13
0.08
0.13
0.15
0.61
0.54
2
0.04
0.08
0.11
0.14
0.81
0.57
3
0.06
0.06
0.09
0.11
0.67
0.63
0.07
0.10
0.15
0.14
0.36
0.54
0.07
0.10
0.06
0.20
0.26
0.64
0.07
0.09
0.06
0.18
0.39
0.73
2
3
Kompletný počet stupňov voľnosti pre všetky série meraní sa vypočíta
=
v
3
vi 54.
∑=
(2.14)
i =1
Výslednú empirickú štandardnú odchýlku prenášaného bodu v oboch polohách prístroja má
tvar, vypočítaná zo všetkých troch sérií meraní:
20
∑r + ∑r
2
1
s=
2
2
+ ∑ r32
v
.
(2.15)
Pomernú presnosť vyjadríme v tvare:
sISO − plumb=
s
h
= 1: ,
h
s
(2.16)
kde s je hodnota vypočítaná zo vzťahu (2.15), h je prevažovaná výška [3].
Odhadovaná odchýlka od zvislice sa môže vyjadriť v smere osi x a y samostatne zo všetkých
sérii meraní a výsledná hodnota odchýlky je vyjadrená vzťahom (2.18):
3
δx =
3
∑δ x
i
i =1
δy =
a
3
=
δ
∑δ y
i
i =1
3
,
(2.17)
δ x2 + δ y2 ,
(2.18)


1
sδ = s 
 .
 3 ⋅ 10 
(2.19)
Empirická stredná chyba odchýlky δ
Č. bodu
Tab. 2.4:Charakteristiky presnosti prístroja č.1
1
2
3
4
5
6
1. meranie
2. meranie
s
sISO − plumb
[mm]
δx
δy
δ
sδ
s
sISO − plumb
[mm] [mm] [mm] [mm] [mm]
δx
δy
δ
sδ
[mm] [mm] mm] [mm]
0.05
1:82900
-0.03
-0.03
0.05
0.010
0.07
1:61100
-0.03
-0.02
0.04
0.013
0.08
1:112800
-0.06
-0.06
0.09
0.014
0.13
1:64900
-0.06
-0.08
0.10
0.024
0.11
1:112800
-0.11
-0.26
0.18
0.020
0.12
1:101200
-0.06
-0.10
0.12
0.022
0.14
1:118700
-0.26
-0.92
0.96
0.025
0.24
1:66500
-0.19
-0.60
0.63
0.045
0.70
1:28700
-0.20
-0.42
0.46
0.128
0.76
1:26600
-0.33
-0.51
0.60
0.139
0.58
1:4100
0.01
-0.23
0.23
0.106
0.76
1:31400
-0.35
-0.60
0.69
0.138
Č. bodu
Tab. 2.5: Charakteristiky presnosti prístroja č.2
1
2
3
4
5
6
1. meranie
2. meranie
s
sISO − plumb
[mm]
δx
δy
δ
sδ
s sISO − plumb
[mm] [mm] [mm] [mm] [mm]
δx
δy
δ
sδ
[mm] [mm] [mm] [mm]
0.08
1:52800
0.24
-0.21
0.31
0.015
0.12
1:37200
-0.23
-0.11
0.25
0.022
0.10
1:88700
-0.18
-0.24
0.30
0.018
0.10
1:83200
-0.38
-0.42
0.57
0.019
0.10
1:121200
-0.34
-0.48
0.59
0.019
0.24
1:51400
-0.59
-0.39
0.71
0.044
0.18
1:92600
-0.37
-0.65
0.75
0.032
0.18
1:92300
-0.45
-0.70
0.83
0.032
0.34
1:59500
-0.72
-0.59
0.93
0.062
0.62
1:32500
-0.72
-0.73
1.02
0.113
0.64
1:37000
-0.52
-0.85
0.99
0.117
0.48
1:49700
-0.66
-0.73
0.99
0.087
21
2.5 Štatistické testy
Pri testovaní je doporučené používať podľa tejto časti STN ISO 17 123 štatistické testy [4].
Tieto testy poskytujú odpovede na štyri otázky, ktoré sú uvedené v tab.2.6. Pre tieto testy sa
za hladinu významnosti uvažuje hodnota α = 0, 05.
Tab. 2.6: Štatistické testy
Otázka
Nulová hypotéza
Alternatívna hypotéza
s >σ
a)
s ≤σ
b)
σ = σ
σ ≠ σ
c)
σx ≠ σy
σx = σy
d)
δ =0
δ ≠0
a) Vypočítaná empirická štandardná odchýlka s je menšia alebo rovná ako jej
prislúchajúca hodnota σ daná výrobcom?
b) Patria dve empirické štandardné odchýlky s a s ,určené z dvoch rôznych súborov
meraní do rovnakej oblasti predpokladajúc, že obe vzorky majú rovnakú prevažovanú
výšku h a rovnaký počet stupňov voľnosti?
Hodnoty empirických štandardných odchýlok s a s môžu byť získané z:
• dvoch nezávislých súborov meraných údajov, realizovaných tým istým prístrojom ale
rôznymi meračmi,
• dvoch súborov meraných údajov, rovnakým prístrojom, realizovaných v rôznych
časových epochách,
• dvoch súborov meraných údajov, realizovaných rôznymi strojmi.
c) Ak je empirická štandardná odchýlka sx x – ovej zložky, rovná empirickej štandardnej
odchýlke s y y- ovej zložky výsledku dosiahnutého prevažovania?
d)
Je odchýlka δ = 0 ? [4].
Otázka a)
Nulová hypotéza H 0 sa nezamieta ak je splnené:
s ≤σ
kde v = 54 .
s ≤σ
χ12−α
,
v
2
χ 0.95
(54)
(2.20)
,
(2.21)
χ12−α (54) = 72,15,
(2.22)
s ≤σ
54
72,15
,
54
s ≤ σ ⋅1,16.
(2.23)
(2.24)
22
Presnosť udávaná výrobcom pre prístroj Zeiss PZL 100 σ = 1: 100 000 = 0,0000100, ak platí
nasledujúci vzťah s ≤ 0,0000116, tak sa nulová hypotéza nezamieta. Hodnota s je získaná
s pomernej presnosti sISO − plumb vypočítanej podľa vzťahu (2.16). V tab.2.7 a 2.8 sú uvedené
hodnoty empirických štandardných odchýlok výsledky štatistických testov pre oba prístroje
a obe etapy merania [4].
Tab. 2.7: Výsledky štatistických testov: Otázka a), prístroj č.1
Č. bodu
1
2
3
4
5
6
s
1. meranie
Výsledok
štatistického testu
s
2. meranie
Výsledok
0.0000121
H 0 sa zamieta
0.0000164
H 0 sa zamieta
0.0000089
H 0 sa nezamieta
0.0000154
H 0 sa nezamieta
0.0000089
H 0 sa nezamieta
0.0000099
H 0 sa nezamieta
0.0000084
H 0 sa nezamieta
0.0000150
H 0 sa zamieta
0.0000348
H 0 sa zamieta
0.0000376
H 0 sa zamieta
0.0000244
H 0 sa zamieta
0.0000319
H 0 sa zamieta
Tab. 2.8: Výsledky štatistických testov: Otázka a), prístroj č.2
Č. bodu
1
2
3
4
5
6
s
1. meranie
Výsledok
s
2. meranie
Výsledok
0.0000189
H 0 sa zamieta
0.0000269
H 0 sa zamieta
0.0000113
H 0 sa nezamieta
0.0000120
H 0 sa nezamieta
0.0000083
H 0 sa nezamieta
0.0000195
H 0 sa zamieta
0.0000108
H 0 sa nezamieta
0.0000108
H 0 sa nezamieta
0.0000168
H 0 sa zamieta
0.0000308
H 0 sa zamieta
0.0000270
H 0 sa zamieta
0.0000201
H 0 sa zamieta
Otázka b)
Nulová hypotéza H 0 sa nezamieta ak je splnená nasledujúca podmienka:
1
s2
≤ 2 ≤ F1−α /2 (v1 , v2 ),
F1−α /2 (v1 , v2 ) s
(2.25)
1
s2
≤ 2 ≤ F0,975 (54,54),
F1−α /2 (54,54) s
(2.26)
F0,975 (54,54) = 1, 71
(2.27)
0,58 ≤
s2
≤ 1, 71.
s 2
(2.28)
23
Výsledky štatistických testov dvoch nezávislých súborov meraní získané rovnakým
prístrojom sú uvedené tab.2.9 [4].
Č. bodu
Tab. 2.9: Výsledky štatistických testov: Otázka b)
1
2
3
4
5
6
Výsledok
s2
s 2 / s 2
s 2
0.00 0.00
0.51 H 0 sa zamieta
0.01 0.02
0.38 H 0 sa zamieta
0.01 0.01
0.84 H 0 sa nezamieta
0.02 0.06
0.34 H 0 sa zamieta
0.49 0.58
0.34 0.58
Prístroj č.2 : Zeiss PZL 100, v.č. 214
283
Výsledok
2
2
2


s
s / s2
s
0.01 0.01 0.44 H 0 sa zamieta
0.01 0.01 1.00 H 0 sa nezamieta
0.01 0.06 0.17 H 0 sa zamieta
0.03 0.03 1.00 H 0 sa nezamieta
0.12 0.38 0.30 H 0 sa zamieta
0.41 0.23 1.78 H 0 sa zamieta
Otázka c)
Nulová hypotéza H 0 sa nezamieta ak je splnená nasledujúca podmienka [4]:
s2
1
≤ x2 ≤ F1−α /2 (vx , v y ),
F1−α /2 (vx , v y ) s y
(2.29)
sx2
1
≤ ≤ F0,975 (27, 27),
F0,975 (27, 27) s y2
(2.30)
v=
54 .
kde v=
x
y
F0,975 (27, 27) = 2,16,
(2.31)
sx2
0, 46 ≤ 2 ≤ 2,16.
sy
(2.32)
Výsledky štatistických testov porovnaním sx x – ovej zložky a s y y- ovej zložky získané
rovnakým prístrojom sú uvedené tab.2.10 a 2.11 [4].
Č. bodu
Tab. 2.10: Výsledky štatistických testov: Otázka c), prístroj č.1
1
2
3
4
5
6
1. meranie
2. meranie
sx2
s y2
sx2 / s y2
1.661
Výsledok
H 0 sa nezamieta
0.005
0.006
0.818
Výsledok
H 0 sa nezamieta
0.005
1.310
H 0 sa nezamieta
0.014
0.020
0.707
H 0 sa nezamieta
0.011
0.013
0.802
H 0 sa nezamieta
0.014
0.015
0.944
H 0 sa nezamieta
0.017
0.021
0.815
H 0 sa nezamieta
0.042
0.089
0.475
H 0 sa nezamieta
0.342
0.645
0.531
H 0 sa nezamieta
0.413
0.740
0.558
H 0 sa nezamieta
0.166
0.507
0.327
H 0 sa zamieta
0.425
0.721
0.589
H 0 sa nezamieta
sx2
s y2
sx2 / s y2
0.004
0.002
0.006
24
Č. bodu
Tab. 2.11: Výsledky štatistických testov: Otázka c), prístroj č.2
1
2
3
4
5
6
1. meranie
2. meranie
sx2
s y2
sx2 / s y2
4.656
Výsledok
H 0 sa zamieta
0.008
0.021
0.365
Výsledok
H 0 sa zamieta
0.010
0.782
H 0 sa nezamieta
0.015
0.006
2.284
H 0 sa zamieta
0.017
0.003
5.062
H 0 sa zamieta
0.053
0.063
0.839
H 0 sa nezamieta
0.050
0.012
4.288
H 0 sa zamieta
0.035
0.027
1.320
H 0 sa nezamieta
0.146
0.084
1.736
H 0 sa nezamieta
0.307
0.463
0.664
H 0 sa nezamieta
0.269
0.554
0.486
H 0 sa nezamieta
0.264
0.192
1.375
H 0 sa nezamieta
sx2
s y2
sx2 / s y2
0.013
0.003
0.008
Otázka d)
Nulová hypotéza H 0 sa nezamieta ak je splnená nasledujúca podmienka [4]:
δ ≤ σ ⋅ t1−α /2 ( v ) ,
(2.33)
δ ≤ σ ⋅ t0,975 ( 54 ) ,
(2.34)
t0,975 (54) = 2, 00,
(2.35)
σδ =
δ ≤
s
,
3 ⋅ 10
(2.36)
s
⋅ 2, 00,
3 ⋅ 10
(2.37)
δ ≤ s ⋅ 0.37.
(2.38)
Výsledky štatistických testov otázky d), t.j či odchýlka zámery sa δ nerovná nule je uvedené
tab. 2.12 a 2.13 [3].
Č. bodu
Tab. 2.12: Výsledky štatistických testov: Otázka d), prístroj č.1
1
2
3
4
5
6
1. meranie
2. meranie
δ
≤
s ⋅ 0,37
0,004
Výsledok
H 0 sa zamieta
0,04
>
0,005
Výsledok
H 0 sa zamieta
>
0,005
H 0 sa zamieta
0,10
>
0,009
H 0 sa zamieta
0,31
>
0,007
H 0 sa zamieta
0,12
>
0,008
H 0 sa zamieta
0,96
>
0,009
H 0 sa zamieta
0,63
>
0,017
H 0 sa zamieta
0,46
>
0,047
H 0 sa zamieta
0,60
>
0,051
H 0 sa zamieta
0,23
>
0,39
H 0 sa zamieta
0,69
>
0,050
H 0 sa zamieta
δ
≤
s ⋅ 0,37
0,05
>
0,09
25
Č. bodu
Tab. 2.13: Výsledky štatistických testov: Otázka d), prístroj č.2
1
2
3
4
5
6
1. meranie
2. meranie
δ
≤
s ⋅ 0,37
0,006
Výsledok
H 0 sa zamieta
0,25
>
0,008
Výsledok
H 0 sa zamieta
>
0,007
H 0 sa zamieta
0,57
>
0,007
H 0 sa zamieta
0,59
>
0,007
H 0 sa zamieta
0,71
>
0,016
H 0 sa zamieta
0,75
>
0,012
H 0 sa zamieta
0,83
>
0,012
H 0 sa zamieta
0,93
>
0,022
H 0 sa zamieta
1,02
>
0,042
H 0 sa zamieta
0,99
>
0,043
H 0 sa zamieta
0,99
>
0,032
H 0 sa zamieta
δ
≤
s ⋅ 0,37
0,31
>
0,30
3. ZÁVER
Výsledkom testovania optického prevažovača Zeiss PZL 100 je určenie empirickej
štandardnej odchýlky určenia polohy bodu zo súboru meraní, pričom počet opakovaní je daný
normou STN ISO 17 123 Časť 7: Optické prevažovacie prístroje. Na základe štatistických
testov uvedených v norme je možné konštatovať či daný prístroj vyhovuje norme, alebo je
potrebná jeho rektifikácia.
Z vykonaných meraní vyplýva, že empirická štandardná odchýlka priamo úmerne narastá
s prevažovanou výškou, pričom pri väčšom prevýšení je meranie zaťažené aj systematickou,
ktorá závisí aj od veľkosti použitej mriežky x – y (rastra). Ak porovnáme vypočítane
empirické štandardné odchýlky získané z experimentálnych meraní s hodnotami udávanými
výrobcom možno konštatovať, že oba prístroje vyhovujú norme do prevažovanej výšky cca
16m. Odpovede na ostané otázky štatistických testov sú v časti 2.5.
Kontrola, overovanie a testovanie geodetických prístrojov a pomôcok sú nevyhnutnou
súčasťou každej geodetickej práce – zákazky. Technické normy stanovujú kritéria
a požiadavky kladené na túto nevyhnutnú súčasť geodetických prác. Nezáväznosť noriem
neznamená ich neplatnosť, ale umožňuje efektívne určiť spoľahlivosť používaného prístroja
a jeho doplnkov na voľbu postupu merania pre konkrétnu meračskú úlohu.
Použitá literatúra
1.
2.
3.
4.
JEŽKO, J.: Testovanie a kalibrácia geodetických prístrojov z pohľadu technických
noriem. In.: Interdisciplinárne aplikácie geodézie, inžinierskej geodézie a
fotogrametrie. Bratislava, Katedra geodézie SvF STU, 2008, 10 s., (CD) ISBN 97880-227-2938-3.
MICHALČÁK, O. a kol.: Inžinierska geodézia II. Alfa - SNTL, Bratislava 1990, s.
357.
BUJŇÁK, L. : Testovanie geodetických prístrojov podľa STN ISO 17 123. Diplomová
práca. Katedra geodézie SvF STU Bratislava 2012, 55s.
STN ISO 17123-7: 2010 Optika a optické prístroje - Postupy na testovanie
geodetických prístrojov. 7. časť: Optické prevažovacie prístroje.
Kontaktní údaje:
Ing. Ján Ježko, PhD., Katedra geodézie, Stavebná fakulta,
Slovenská technická univerzita v Bratislave, Radlinského 11, 813 68 Bratislava,
tel.: 02/59274 338, e-mail: [email protected]
26
CONSTRUCTION IN OPOLSKIE VOIVODSHIP STRUCTURE:
ECONOMIC SIGNIFICANCE
Mirosława Szewczyk, Rafał Parvi
Abstract
Construction plays an essential role in the economic development of Opolskie Voivodship.
The main purposes of the study are the identification, description and explanation of changes
which have occurred in Opolskie Voivodship economic composition with particular regard to
section F (construction). Based on the software named GRETL, we tested the Granger
causality between sold production of industry and sold production of construction. The data
are taken of the free on-line data base of Central Statistical Office of Poland.
Key words: Opolskie Voivodship, construction, changes
1
INTRODUCTION
Regional economic structure is defined as the composition and patterns of various
components of the regional economy including: production, employment, consumption, trade.
The question what determines growth in regions and how regions develop growth paths is a
fundamental one. Structural changes are in the interest of researchers, policymakers, and the
general public. The changes in economic activity in Opolskie Voivodship is one of the most
research topics. Adamska, Jasińska-Biliczak, Malik, Mach, Łobos, Szewczyk, Romaniuk,
Ruszczak, Tłuczak, J. Zygmunt and Z. Zygmunt discussed problems of key development
areas for Opolskie Voivodship [1, 5, 6, 10, 11, 12, 13, 14, 15, 16, 17, 18].
The main purposes of the study are: the identification, description and explanation of changes
which have occurred in Opolskie Voivodship economic composition with particular regard to
section F (construction). We investigate the relationship between industry and construction at
the regional level The study uses data from the Central Statistical Office of Poland (CSO).
The data by the kinds of activity are presented in accordance with Polish Classification of
Activity (PKD 2007) 1. The data are taken of the free on-line data base of Central Statistical
Office 2.
2
ECONOMIC DEVELOPMENT OF OPOLSKIE VOIVODSHIP
Construction plays an essential role in the economic development of Opolskie Voivodship
[17]. It contributes to about 630 mln EUR of sold production in Opolskie Voivodship (2012),
and represents a significant employer. The subchapter describes production, and employment
data. These data provide the basis for further analysis, and give a picture of the recent
historical trends of sold production and employment (tables 1-2). Overall the construction
employed 8 thousand of total employment, corresponding to 8% of employment in enterprise
sector. Public sector is a major client of construction. The key drivers for construction sector
are EU funds. It concerns infrastructural investments, first of all, in the area of road
1
Polish Classification of Activities 2007 (PKD 2007) was compiled on the basis of Statistical Classification of
Economic Activities in the European Community – NACE Rev. 2. PKD 2007 was introduced on 1st January
2008 by the decree of Council of Ministers to replace the formerly applied PKD 2004.
2
available at the following address http://www.stat.gov.pl.
27
construction and modernisation of rail connections. It should be mentioned that the
construction has various links to quarrying sector, manufacturing, production and
consumption of energy, transportation, etc.
Table 1. Sold production of industry and construction (in million PLN) in Opolskie
Voivodship, 2008-2012
Construction
Industry
Construction and assembly production*
Year
(total)
Construction
Civil
Specialised
ogółem
Total
Total
of buildings
engineering construction activities
2008 20,994.1 2,201.6
914.4
404.5
384.2
345.1
2009 19,702.2 2,561.5 1,133.8
434.4
421.1
274.7
2010 17,713.2 2,752.6 1,130.2
478.8
660.9
287.4
2011 19,732.2 3,182.8 1,420.9
485.4
618.7
316.9
2012 21,155.2 2,650.3 1,201.9
417.3
515.3
269.3
* - Excluding sub-contractors
1 PLN = 0,24 EUR
Source: Statistical Bulletyn of Opolskie Voivodship. Opole: CSO.May 2009. pp. 55-59;
Statistical Bulletyn of Opolskie Voivodship. Opole: CSO. May 2011. pp. 55-59; Statistical
Bulletyn of Opolskie Voivodship. Opole: CSO. August 2013. pp. 55-59.
Trends in employment are perhaps more interesting than trends in sold production. In 2008,
100 thousand workers were employed in enterprise sector in Opolskie Voivodship. Five years
later, only 96 thousand workers were employed. Employment in enterprise sector has been
reduced, but employment in the construction has increased (table 2).
Table 2. Average paid employment in enterprise sector in Opolskie Voivodship, 2008-2012
Wyszczególnienie
2008
2009
2010
2011
2012
Total
100,078 98,488 96,636 96,830 96,267
Section F - Construction
7,117
7,840
8,125
8,314
8,370
Źródło: CSO data (2013) http://www.stat.gov.pl
According to the CSO data section F (construction) accounted in 2012 for a total of 13
thousand enterprises (table 3). The number of entities in section F has increased. There were
13,267 in 2012 entities compared to 12,738 in 2009 (a 4 per cent increase).
Table 3. National economy entities in the REGON register in Opolskie Voivodship, 20092012
Specification
Total
- Construction of buildings (division 41)
- Civil engineering (division 42)
- Specialised construction activities (division 43)
Source: CSO data (2013) http://www.stat.gov.pl
2009
95,481
12,738
4,274
512
7,952
2010
99,118
13,278
4,316
590
8,372
2011
97,560
13,136
4,208
626
8,302
2012
98,741
13,267
4,189
683
8,395
28
3
SECTORAL SPECIALISATION OF OPOLSKIE VOIVODSHIP
The sectoral specialisations of the regions can be analysed in two stages: location quotient and
number of gazelles 3. Location quotients (LQ) are calculated allowing a comparison of the
level of sectoral activity across geographic areas (table 4). The traditional calculation
compares sectoral shares in a regional area, to sectoral shares in the nation (Poland). The ratio
indicates a relative level of concentration in the region. Coefficient LQ larger than 1 indicates
a higher concentration, value of LQ=1 indicates the concentration is the same as the national,
and a coefficient LQ below 1 indicates a lower concentration .High LQ is potential predictor
for strategising with a smart regional specialisation policies.
Rapidly growing companies, so-called gazelles, are important for an economy
competitiveness, and are increasingly recognised by policy-makers. Gazelles are believed to
be important job creators, important innovators and to have a relative high labour
productivity. There were 44 gazelles with revenues above 5 milion PLN in Opolskie
Voivodship in 2012 (41 gazelles in 2011). Gazelles exist in many sections. Construction is
among the sections with the highest share of gazelles in Opolskie Voivodship economy 4 (7%15% in 2009-2012) with 5 gazelles in 2011 (De Silva, Sobet, IXO Serwis, Mostostal
Kędzierzyn, Technodrew Polska Wyposażenie Wnętrz) and 3 gazelles in 2012 (Mikrotuneling
Partner System, Mostostal Kędzierzyn, Technodrew Polska Wyposażenie Wnętrz).
Table 1. Location Quotient: Opolskie Voivodship
Wyszczególnienie
- Construction of buildings (division 41)
- Civil engineering (division 42)
- Specialised construction activities (division 43)
2009
2010
1,12
1,19
0,64
1,15
1,12
1,16
0,70
1,15
Source: M. SZEWCZYK, A. TŁUCZAK, B. RUSZCZAK. Analiza koncentracji, [in:]
Projekcja rozwoju inicjatyw klastrowych w województwie opolskim, (Eds.) W. Duczmal, W.
Potwora. Opole: Wydawnictwo Instytut Śląski Sp. z o.o., Wyższa Szkoła Zarządzania
i Administracji w Opolu, 2011. p. 91.
http://www.efs.gov.pl/AnalizyRaportyPodsumowania/baza_projektow_badawczych_efs/Docu
ments/9_Projekcja_rozwoju_inicjatyw_klastrowych.pdf
4
SOLD PRODUCTION OF INDUSTRY AND SOLD PRODUCTION
OF CONSTRUCTION: LOOKING FOR THE CAUSAL RELATION
3
There is no agreement on the definition of gazelles. Birch defines them as “A business establishment which has
achieved a minimum of 20% sales growth each year over the interval, starting from a base-year revenue of at
least $100,000.’’ Organization for Economic Cooperation and Development (OECD) defines high-growth
enterprises as enterprises with an average employment growth rate exceeding 20% p.a. over a 3-year period and
with ten or more employees at the beginning of the period. See: [2, 3].
4
Forbes Diamonds is a ranking of the fastest growing companies with revenues above 5 milion PLN operating
in the market. The list of Forbes’ Diamonds has been elaborated on the basis of Swiss method of company value
pricing. This method includes the financial results and the property value of particular companies. It allows also
to measure the company potential considering the largeness of realized investments and the ability to increase
sales and profits Forbes prepares a list of the entities, to which it grants a positive credibility rating and confirms
that:
- they are profitable (on the basis of the EBIT and ROA indices),
- they have high current liquidity and no arrears,
- they record a positive financial result and a value of shareholders' equity in the three years.
29
The paper applies modern time series methods to the forecasting problem. We want to explore
Granger causality between sold production of industry and sold production of construction by
regressing one variable on its lagged values, and testing whether adding lagged values of the
other variable contributes significantly to the explanation of the dependent variable (based on
the software package called GRETL). The concept of Granger causality test is explored when the
coefficients of the lagged of the other variables is not zero.
Y t = α 0 + α 1 Y t-1 + … + α p Y t-p + β 1 X t-1 + … + β p X t-p + ε t
X t doesn't Granger cause Y t if all lagged coefficients for X t are zero (β 1 = β 2 = … = β p = 0).
We look for basic relationships between sold production of industry and sold production of
industry in Opolskie Voivodship using quarterly data. Figure 1 provides sold production of
industry and construction in Opolskie Voivodship for Q1 2006 - Q2 2013.
Figure 1. Sold production of industry and construction in Opolskie Voivodship (in mln PLN)
for Q1 2006 - Q2 2013 (t=1 for Q1 2006).
Source: own presentation base on CSO data.
The following notation is used:
INDUSTRY – sold production of industry (in million PLN)
CONSTRUCTION - sold production of construction (in million PLN).
Table 5. Basic statistics
Variable
Specification
Mean (milion PLN)
Standard deviation (milion PLN)
Coefficient of variation (%)
Source: own calculations, GRETL.
INDUSTRY
4,994
431
0.09
CONSTRUCTION
567
179
0.32
To discover the unit roots, the Augmented Dickey-Fuller test (ADF) is used. In the table 6 the
p-values are reported (value greater than 0.10 indicates non-stationary time series). Table 6
exhibits the results of the Augmented Dickey Fuller (ADF) test which shows that
INDUSTRY is stationary at level and CONSTRUCTION is stationary at level.
30
Table 6. Results of Augmented Dickey-Fuller Test (ADF) for Unit Root
Results of unit root test with intercept
Results of unit root test with trend
and intercept
Variable
ADF
p-value
ADF
p-value
INDUSTRY
-3.65
0.011**
-3.86
0.027**
CONSTRUCTION
-4.38
0.002***
-5.03
0.002***
Note: The null hypothesis is that the series is non-stationary, or contains a unit root.
***, **, * Indicate significance at the 0.01, 0,05 and 0.10 levels
The optimum lag length based on Schwarz criterion is k=1. We estimate a set of models to
observe the causal relation between variables. The results of Granger causality test are
reported in table 7. Sold production of industry does not Granger cause sold production of
construction. Sold production of construction Granger cause sold production of industry.
These results must be interpreted with one limitation in mind: the limited availability of long
time series data. Our analysis takes into account only Q1 2006 - Q2 2013 period. Further
studies should aim at evaluating the long-term relation existing between sold production of
industry and sold production of construction
Table 7. Results of Granger causality test
Specification
H 0 : INDUSTRY does not Granger cause CONSTRUCTION
H 0 : CONSTRUCTION does not Granger cause INDUSTRY
Lags
1
1
Decision
Do not reject H 0
Reject H 0
The function of CONSTRUCTION and INDUSTRY is:
INDUSTRY t = 1.12451* INDUSTRY t-1 – 1.04203 *CONSTRUCTION t-1
The results are shown in table 8.
Table 8. OLS Estimation, dependent variable: INDUSTRY t
Specification
Coeff.
Std. Error
INDUSTRY t-1
1.12451
0.05528
CONSTRUCTION t-1
-1.04203
0.46589
***, **, * Indicate significance at the 0.01, 0,05 and 0.10 levels
t-Student
20.34
-2.24
p-value
0.000***
0.034**
CONCLUSIONS
Opolskie Voivodship economic structure does not appear to have changed significantly since
2008. Employment in enterprise sector in Opolskie Voivodship fell from 100,078 in 2008 to
96,267 in 2012 which was 96.2% of the 2008 level. The section that has increased its share of
employment is construction. The Opolskie Voivodship construction employs over 8 thousand
people, corresponding to 8% of employment in enterprise sector. The construction is very
important sector of the Opolskie Voivodship economy and there are a lot of signs showing
that it will remain the growth leader for the next few years. The effects of global deceleration
can also influence the Opolskie Voivodship economy, but he outlook for the sector in terms of
output, sales and employment is largely positive.
Based on the software named GRETL, we tested the Granger causality. The empirical
evidence shows that sold production of construction Granger cause sold production of
industry.
31
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czych_efs/Documents/9_Projekcja_rozwoju_inicjatyw_klastrowych.pdf
SZEWCZYK, M., ZYGMUNT, A. Możliwości rozwoju branży budowlanej w
województwie opolskim. Barometr Regionalny. Analizy i Prognozy. No. 4(26),
Zamość: Wyższa Szkoła Zarządzania i Administracji w Zamościu. 2011. pp. 75-84.
ISSN 1644-9398, http://br.wszia.edu.pl/zeszyty/pdfs/br26_10zygmunt.pdf
ZYGMUNT, A., ZYGMUNT, J. Istota i znaczenie działalności inwestycyjnej
opolskich przedsiębiorstw w kreowaniu rozwoju regionu [in:] Programowanie
rozwoju regionu. Ład ekonomiczny i środowiskowo-przestrzenny. (Ed.) Krystian
Heffner. Opole: Wydawnictwo Instytutu Śląskiego. 2007. pp. 88-99.
Contact
Mirosława Szewczyk, PhD
Opole University of Technology, The Faculty of Economics and Management
Waryńskiego 4, 45-047 Opole, Poland
Tel: (+48) 77 449 88 00
Rafał Parvi, PhD
Opole Higher School
Kośnego 72, 45-001 Opole, Poland
33
SPATIAL AUTOCORRELATION OF INDICES OF PRODUCTION IN
CONSTRUCTION IN EUROPEAN UNION
Agnieszka Tłuczak
Abstract
The construction industry is the largest industrial sector in Europe, it is of primary importance
in terms of the production of capital goods. Construction in the EU produces an average of
48.9% of fixed assets. Since 2000, it can be observed decrease in construction output. The
crisis, which took place in 2007, exacerbated this tendency. The purpose of this article is to
identify the type and strength of spatial relationships using spatial autocorrelation statistics.
This statistics allow to specify the spatial structures and capture ongoing changes the
construction sector.
Key words: construction, indices of production, spatial autocorrelation
1
THE CONSTRUCTION IN EU
The production index for construction is a business cycle indicator which measures
monthly changes in the price adjusted output of construction. The construction production
index corresponds to the industrial production index.
The development of overall construction was very similar for the EU-28 and the Euro area
(EA-17). However there a noticeable differences between the development of the construction
of buildings (residential and non-residential) which accounts for around 78 % of total
construction and the development of the construction of civil engineering works (e.g.
railways, roads, bridges, airport runways, dams) which accounts for around 22 % of total
construction 1.
The crisis in the building sector hit all EU-28 countries albeit to a different extent. All
countries experienced a decline in building production ranging from an extreme reduction of 54.4 % in Lithuania in 2009 to almost stable activity levels in Germany and Austria. In
several countries (e.g. the Baltic countries, Spain, France, Hungary) growth rates had already
begun to move downwards around the year 2005 while in several other countries the drop in
building activities happened in a more sudden way and was shorter.
The largest annual decline in June 2012 were observed in Portugal - 18.9 percent, the
UK - 15.5 percent, Hungary - 11.1 percent and Slovakia - 11 percent. The year over year
increase in production in the construction sector were recorded in Sweden (14.6 percent),
Germany (3 percent) and Romania (0.1 percent).
Taking into account the different sectors, according to Eurostat in the construction sector
output fell by 3.2 percent in the euro area and the EU-27 by 5.6 percent in June year on year.
However, in the field of civil engineering, production fell by 3.8 percent in the eurozone and
9.3 percent in the EU, compared with June 2011.
1
http://epp.eurostat.ec.europa.eu/statistics_explained/index.php/Construction_production_%28volume%
29_index_overview
34
2
METHODOLOGY
Since the 1950s, several spatial methods of analysis have been developed and modified to
improve our ability to detect and characterize spatial patterns. These stem from several fields
of study, having more or less different goals, mathematical approaches and underlying
assumptions 2.
In its most general sense, spatial autocorrelation is concerned with the degree to which
objects or activities at some place are similar to other objects or activities located nearby. Its
existence is reflected in the proposition which Tobler (1970) has referred to as the "first law
of geography: everything is related to everything else, but near things are more related than
distant things". Spatial autocorrelation can be interpreted as a descriptive index, measuring
aspects of the way things are distributed in space, but at the same time it can be seen as a
causal process, measuring the degree of influence exerted by something over its neighbors’.
The aim of the analysis is to determine the spatial interrelationships and interactions
between neighboring objects, in this case the EU countries. Observations made at different
locations may not be independent. For example, measurements made at nearby locations may
be closer in value than measurements made at locations farther apart. Spatial autocorrelation
measures the correlation of a variable with itself through space, it can be positive or negative.
Positive spatial autocorrelation occurs when similar values occur near one another and
negative - occurs when dissimilar values occur near one another 3.
The Moran’s index and Geary’s coefficient summarize the strength of associations
between responses as a function of distance, and possibly direction. These indices are usually
applied in ecology and geographical sciences. Fortin et al., for example, used these spatial
autocorrelation coefficients to compare the capacity of different sampling designs and sample
sizes to detect the spatial structure of a sugar-maple tree density data set gathered from a
secondary growth forest. Moran’s index is one of the oldest indicators of spatial
autocorrelation. It is applied to zones or points which have continuous variables associated
with their intensities. For any continuous variable, x i , a mean can be calculated and the
deviation of any observation from that mean can also be calculated. The statistic then
compares the value of the variable at any one location with the value at all other locations. It
is formally defined by:
n
I=
S0
∑∑ w ( x − x )( x
∑ (x − x )
ij
i
i
j
− x)
j
2
i
i
where: x is the mean of the x variable, wij are the elements of the weight matrix 4, and S0 is
the sum of the elements of the weight matrix: S0 = ∑∑ wij .
i
j
Moran’s index varies between –1.0 and +1.0. When nearby points have similar values,
the cross-product is high; and when nearby points have dissimilar values, the cross-product is
low. In other words, an I value which is high indicates more spatial autocorrelation than an I
which is low 5. In the absence of autocorrelation and regardless of the specified weight matrix,
2
Anselin, L. (1995). Local indicators of spatial autocorrelation – LISA, Geographical Analysis 27, 93 – 115.
Cressie, N.A.C. (1993). Statistics for Spatial Data ,Wiley, New York Perry, J.N. (1995). Spatial analysis by
distance indices, Journal of Animal Ecology 64, 303 – 314
3
Gunaratna N., Liu Y., Park J., Spatial Autocorrelation, http://www.stat.purdue.edu/~bacraig/
SCS/Spatial%20Correlation%20new.doc
4
The weight matrix can be specified in many ways: (1) the weight for any two different locations is a constant,
(2) all observations within a specified distance have a fixed weight, (3) K nearest neighbors have a fixed weight,
and all others are zero, (4) weight is proportional to inverse distance, inverse distance squared, or inverse
distance up to a specified distance.
5
Diagnosis of lung nodule using Moran’s index and Geary’s coefficient in computerized tomography images
35
the expectation of Moran’s I statistic is −1/(n − 1) , which tends to zero as the sample size
increases. For a row-standardized spatial weight matrix, the normalizing factor S0 equals n
(since each row sums to 1), and the statistic simplifies to a ratio of a spatial cross product to a
variance. A Moran’s I coefficient larger than −1/(n − 1) indicates positive spatial
autocorrelation, and a Moran’s I less than −1/(n − 1) indicates negative spatial
autocorrelation 6.
Geary’s C statistic (Geary 1954) is based on the deviations in responses of each
observation with one another:
n −1
C=
2S0
∑∑ w ( x − x )
∑ (x − x )
ij
i
i
2
j
j
2
.
i
i
The values of C typically vary between 0 and 2. The theoretical value of C is 1, that
indicates that values of one zone are spatially unrelated to the values of any other zone.
Values less than 1 (between 0 and 1) indicate positive spatial autocorrelation while values
greater than 1 indicate negative spatial autocorrelation.
This coefficient does not provide the same information of spatial autocorrelation given by
Moran’s index, because it emphasizes the differences in values between pairs of observations
comparisons rather than the covariation between the pairs. So the Moran’s index gives a more
global indicator whereas the Gearys coefficient is more sensitive to differences in small
neighborhoods 7.
Moran’s I is a more global measurement and sensitive to extreme values of , whereas
Geary’s C is more sensitive to differences in small neighborhoods. In general, Moran’s I and
Geary’s C result in similar conclusions. However, Moran’s I is preferred in most cases since
Cliff and Ord (1975, 1981) have shown that Moran’s I is consistently more powerful than
Geary’s C 8.
In addition to global statistics calculated by the local statistics. Local measures inform
neighboring provinces observed situation in relation to the. It can be assumed that the
interpretation of the local statistics are similar to the global statistics. If you get a negative
value for the local Moran's statistics, we can conclude that the i-th country is surrounded by
countries (neighbors) are different from each other due to the test feature. In the case of
positive talk about similar countries (neighbors) in the i-th country setting. Local statistics are
called LISA statistics. Local Moran statistic is given by formula:
n
I(w) =
(x i − x )∑ w ij (x i − x )
i= j
n
∑ (x
− x)
.
2
i
i= j
6
7
Da Silva E., Silva A., De Paiva A., Nunes R., Diagnosis of lung nodule using Moran’s index and Geary’s
coefficient in computerized tomography images
8
36
3
THE RESULTS OF THE RESEARCH
The study included 27 member states of the European Union The research used the data
from the Central Statistical Office from the years 2005 – 2012 9. The indices of production in
construction in European Union was taken under consideration. Table 1 shows the statistical
characteristics of the indices.
Table 1 Statistical characteristics of the indices of production in construction in European
Union.
year 2005
2012
mean
105,5
94,9
standard deviation
12,2
9,6
coefficient of variation
12%
10%
Source: Own calculation.
Analyzing the results contained in Table 1, it is clear that variable taken under
consideration isn't varied (value of the coefficients of variation exceeds the value of 10%).
The data shows a decreasing trend of average of indices of production in construction.
The study of spatial autocorrelation of indices of production in construction have been
carried out under the assumption of contact matrix W. The calculated value of the global I
Moran's statistics indicate that in the adopted study period can be observed the existence of a
moderate spatial autocorrelation. In 2005 is negative, it means that the areas are not similar to
each other. In 2012 the I Moran’s statistics is positive, that there is a tendency to focus on
individuals with similar levels of indices of production in construction. All obtained values of
I Moran's statistics are statistically significant (p-value <0.05) (Fig. 1-2).
Fig. 1 Moran’s I scatterplot for the indices
of production in construction in 2005 .
Source: calculations in the GeoDa.
Fig. 2 Moran’s I scatterplot for the indices
9
of production in construction in 2012.
http://stat.gov.pl/gus/5840_11289_PLK_HTML.htm
37
Fig. 3 The map of objects adherence to the quarters on Moran’s point graph for the variable in
2005
Fig. 4 The map of objects adherence to the quarters on Moran’s point graph for the variable in
2012
Figure 3 and 4 distinguishes spatial clusters of similar values of Moran’s local
statistics. The diagnosed local spatial autocorrelation of regions in European Union
considering the values of indices of production in construction, a result of clustering of
regions with the high level indices of production in construction.
The dependence direction underwent slight changes during the analyzed years. This
leads to conclusion about the necessity of intensified studies and explanation of the causes of
this phenomenon.
On the basis of statistically significant I Moran’s statistics the occurrence of positive in
2012 and negative in 2005 spatial autocorrelation which characterized the production in
construction during the studied periods should be stated – the neighboring regions were alike
as far as the value levels of indices of production in construction.
38
4
SUMMARY
The statistics of spatial autocorrelation inform about the kind and the strength of spatial
dependence making it possible to determine the spatial structures and capture occurring
changes.
On the basis statistically significant I Moran’s statistics the occurrence of positive spatial
autocorrelation which characterized the production in construction level in EU during the
years 2005 – 2012 should be stated. The neighboring regions were alike as far as the value
levels of production in construction were concerned. At the same time the necessity of the
intensified studies on the production in construction value in EU regions should be stated, the
tendency does not seem to be fixed (which can indicate the changes in production directions).
Sources
1.
BIVAND R., Autokorelacja przestrzenna a metody analizy statystycznej w geografii
[w:] red. Z. Chojnicki, Analiza regresji w geografii, PWN1980, p. 23–38.
2.
DE SIANO R., D’UVa M., Italian regional specialization: a spatial analysis,
Università degli Studi di Napoli- Parthenope, Discussion Paper 2012, Nr 07,
http://www.crisei.uniparthenope.it/DiscussionPapers.asp
3.
http://www.igipz.pan.pl/tl_files/igipz/ZGWiRL/ARP/01.Znaczenie%20rolnictwa%2
0w%20gospodarce%20Polski.pdf
4.
http://www.stat.gov.pl/bdl/app/dane_podgrup.dims?p_id=754325&p_token=0.03135
731145684251
5.
JANC K., Zjawisko autokorelacji przestrzennej na przykładzie statystyki I Morana
oraz lokalnych wskaźników zależności przestrzennej (LISA). Wybrane zagadnienia
metodyczne. Dokumentacja Geograficzna, nr 33, IGiPZ PAN, Warszawa 2006
6.
KOPCZEWSKA K., Ekonometria i statystyka przestrzenna z wykorzystaniem
programu R CRAN, CeDeWu. Warszawa 2006.
7.
OJRZYŃSKA A., TWARÓG S., Badanie autokorelacji przestrzennej krwiodawstwa
w Polsce, Acta Universitatis Lodziensis Folia Oeconomica, nr 253, 2011.
8.
PAELINCK J. H. P., KLAASSEN L. H., Ekonometria przestrzenna, PWN,
Warszawa 1983, s. 14–22.
9.
Rocznik statystyczny rolnictwa 2012, Warszawa, http://www.stat.gov.pl/cps/rde/xb
cr/gus/rs_rocznik_ rolnictwa_2012.pdf
10. SALAMON J., Badania autokorelacji przestrzennej rozwoju infrastruktury
technicznej obszarów wiejskich województwa Świętokrzyskiego z wykorzystaniem
statystyki I Morana, w: Infrastruktura i ekologia obszarów wiejskich, nr 8/2008, s.
207-214.
11. TOBLER W. R., A computer model simulating urban growth in Detroit region,
„Economic geography” 1970/46(2), s. 236.
12. WOŹNIAK A., SIKORA J., Lokalne wskaźniki występowania zależności
przestrzennej sieci wodociągowej w gminach woj. Małopolskiego, infrastruktura i
ekologia terenów wiejskich, Nr 4/2/2007.
Contact
Dr. Agnieszka Tłuczak, Ph.D.
Opole University
Ozimska 46a, Opole, Poland
39
AERODYNAMIC QUANTIFICATION - FACTOR INFLUENCING
HEAT LOSSES CAUSED BY VENTILATION
Iveta Bullová
Abstract
So-called aerodynamic quantification of buildings is necessary to specify the parameters of
indoor climate and heat losses of buildings caused by ventilation with the use of simulation
methods which accept the variability of the climate parameters in time. Aerodynamic
quantification takes into account complex effect of wind and a particular building‘s
parameters. The article suggests the methodics of aerodynamic quantification for a simplified
reference building and the impact of such quantification on the intensity of air exchange
which influences the parameters of indoor climate parameters and heat losses due to
ventilation. This article was created during the grant project VEGA 1/1060/11 “Monitoring of
changes in physical parameters of envelope constructions in quasi-stationary conditions”.
Key words: indoor climate, aerodynamic quantification, heat losses due to ventilation.
1
INTRODUCTION
The intensity of air exchange significantly influences the heat losses of buildings – the natural
unregulated ventilation, as well as the micro climate of the building interior.
Air exchange rate - n - can be expressed:
n = 3600 . V inf /V m = 3600 . [ Σ(i V,l . l) . ∆p C
(1)
m
] / Vm
(1/h)
– amount of infiltrated air in the room with natural airflow, m3
- room volume , m3
- gap permeability coefficient, m3/(m.s.Pa0,67)
- length of the gap, m
∆p C - total air pressure difference, Pa
V inf
Vm
i l,v
l
To predict the intensity of air exchange with the use of simulation methods, the ones
accepting the variability of the climate parameters in time along with complex aerodynamic
impact on building, we need to account the effect of wind and building’s parameters which
leads us to a so-called aerodynamic quantification of buildings.
The aerodynamic effects on buildings are various and change with dependence on the
building shape and size, the position of buildings within urban configuration in a particular
built-up area and also orientation towards the main wind currents. The building with its
features – shape, surface, air permeability – on the other hand influences the air current in its
immediate surroundings and the change of pressure conditions in the building’s interior.
The article suggests the methodics of aerodynamic quantification for a simplified reference
building with the emphasis on specification of aerodynamic coefficients and comparison of
exact results. Out of many factors emerging from the building-wind interaction, the article
mainly deals with the layout, mutual ratio and size of the opening constructions within the
building’s casing construction for a particular building type from the point of view of space
and height proportionality.
40
The results in the article were analysed and quantified for simplified – modified buildings of
a rectangular shape, with various orientation towards the wind currents and variable layout of
the orifice constructions on the individual sides of the building.
2
CHARACTERISTICS OF AERODYNAMIC EFFECTS ON SIDING
CONSTRUCTIONS
The basic physical parameters of the air exchange rate is the total air pressure difference ∆p c
arising due to the effects of wind ∆p v at different temperatures and external and internal
environment ∆p θ .
The result of these combined factors is the total air pressure difference ∆p c , which can be
expressed:
∆p C =∆p θ +∆p v =h.g.(ρ ae -ρ ai )+C p .0,5.v2.ρ ae
(Pa)
(2)
In the aerodynamics of buildings, the effects of wind on the siding constructions are
manifested in form of differential pressure – Δp v – expressed as :
v 2 .ρ e
∆pv = C p
2
(Pa)
(3)
C p - total aerodynamic coefficient (-)
v - air velocity (m/)
ρ e - outside air density (kg/m3)
Since the wind is the most variable meteorological elements in the surface layer of the
atmosphere, the pressure differential quantification due to the effects of wind ∆p v quite
complicated.
To quantify the differential pressure of air from the wind, it is necessary to know:
- outdoor climate parameters - wind speed, outside air density
- aerodynamic parameters of the building - the total aerodynamic coefficient consisting of
aerodynamic coefficients of external and internal pressure
External climatic parameters are obtained from measurements on hydro-meteorological
stations and the use of computer simulations are processed in the test reference years at hourly
intervals.
Determination of air density, which are temperature dependent "θ e " is possible by:
ρ θ = 353,196 / (273,16 + θ e )
(kg/m3)
(4)
Wind speed is measured at hydro-meteorological station of 10 m above the open ground
(m/s). The nature and speed of the airflow, however, varies depending on the height above the
terrain and urban buildings and its modification in the amount of expressed:
v Z =k.v 10, MET
( m/s)
(5)
v 10,MET -wind speed measured at hydro-meteorological stations at 10 m height
k - coefficient of variation - indicating the impact of urban buildings and the height above the
ground-table 1 [2].
41
Table 1 - Values of the coefficients of transforming wind speed over ground
Values of the coefficients of transforming wind speed k
Height above ground
10
15
20
25
30
35
40
45
50
Center of large cities
0,65
0,75
0,83
0,9
0,95
1,01
1,06
1,1
1,14
Suburbs
0,65
0,72
0,78
0,82
0,86
0,9
0,93
0,96
0,99
In the building– wind interaction, much more complicated seems to be the quantification of
aerodynamic parameters of the building – total aerodynamic coefficient C p .
3
SPECIFICATION
BUILDINGS
OF
AERODYNAMIC
PARAMETERS
OF
Aerodynamic quantification expressed overall aerodynamic coefficient C p =C pe –C pi (-) takes
into account the effects of variable wind with the parameters of the building.
Airflow - wind - around the building raises pressure (suction), which is expressed in external
aerodynamic coefficient C pe (-), depending mainly on the geometric shape of the building and
a plan intended spatial geometry and wind direction.
Values of external aerodynamic coefficients are obtained by measuring the wind tunnels for
so-called. "Solid model", which does not reflect the impact of the shape of the holes.
The air permeability of opening constructions causes the change of external and internal
pressure. That is why, for wind effects, the size and dimension of internal aerodynamic
coefficient must be taken into account. The specification of the value of internal aerodynamic
coefficient C pi is quite difficult in real conditions that is why the values C pi can be specified
for simplified buildings – the ones without internal ties, the openings placed in the
circumferential walls, with air impermeable construction of ceilings and roof. Supposing the
above mentioned facts, internal aerodynamic coefficient C pi can be quantified according to
[3] as a function of the ratio of joint filler structures on the windward side of the building to
the sum of joint filler structures on the remaining three sides of the building.
 S (+ ) 

C = f (a ) = f 
S 
pi
 (− ) 
(6)
S (+) – total length of liaison joints of the window on the windward side the building
S (-) – total length of contact joints window pane to the other 3 sides of the perimeter wall
3.1. Determination of geometry and basic classification of the reference building
A selected reference building with 8 floors (design height of the floor is 2,8m)
is rectangular and its ground-plan has these dimensions:
lenght : l = 50 m, widht b = 18 m , height h = (2,8 x8) =
22,4 m
According to [1] the reference building can be
classified as :
the middle building with a height
15 m < h = 22,4 m < 50 m → buildings to 15 floors
- the geometry is of the fround plan l / b = 50/18 ≈ 3
42
- the plate type building with spatial proportionality: 0,5 ≤ h / b = 1,25 ≤ 1,5 and with surface
area proportionality:
1,5 ≤ l / b = 2,8 ≤ 4,0
3.2. Determination of internal aerodynamic coefficients and the total aerodynamic
coefficient for the reference building
In the reference building is outlined methodology determinations of internal aerodynamic
coefficients C pi . At the C pi quantification within the reference building, the rate of windows
on the particular sides was considered 3:1. The surface of the windows` contact joints on the
longer side is marked as S 1 = S 3 (S BC = S AD ) and on the shorter side as S 2 = S 4 (S AB = S DC ).
Internal aerodynamic coefficient C pi (-) for the analyzed reference building can be determined
from the graphical C pi =f (a) dependence for selected types of buildings [1]:
Wind direction α = 00, 3600
S 1 = S 3 = 3S 2 = 3S 4 ⇒
S (+ )
3S 2
S1
a=
=
=
= 0,6
S (− ) S 2 + S 3 + S 4 S 2 + 3S 2 + S 2
Wind direction α = 90 0
S 1 = S 3 = 3S 2 = 3S 4 ⇒
S (+ )
S2
S2
=
=
= 0,14
a=
S ( − ) S 1 + S 3 + S 4 3S 2 + 3S 2 + S 2
S (+) – total length of liaison joints of the window on the windward side the building
S (-) – total length of contact joints window pane to the other 3 sides of the perimeter wall
Based on the above methodology, were set the values of internal aerodynamic coefficients C pi
=f (S (+) /S (-) ) dependence for selected types of buildings [1], which were considered variable
rate openings 2:1, 3:1 and 4:1 [1]. Value of the internal and overall aerodynamic coefficients
are shown in Table 2.
Table 2 - The values of internal and overall aerodynamic coefficients for different ratios of
holes
Values of C pi
Wind direction
Values of C p =C pe - C pi
Cp=
C pe
2:1
3:1
4:1
2:1
3:1
4:1
00,3600
+ 0,7
- 0,2
- 0,15
- 0,1
0,9
+ 0,85
+0,8
900, 2700
- 0,5
- 0,6
- 0,8
-1
+0,1
+ 0,3
+ 0,5
4 INTERACTION OF AIR EXCHANGE RATE AND VENTILATION
HEAT LOSSES
In the winter time the infiltration brings the exchange of fouled air for the fresh one but also
the supply of cold air form the outside.
43
If we followed the thermal comfort of the internal environment is necessary to warm the air.
Ventilation heat loss of the room Ф v can be expressed as:
Ф v = 1200 . Σ(i L,V .l).∆p C m.(θ ai - θ e )
(7)
Ventilation heat loss coefficient H v can be determined by the air exchange rate:
H v =0,33.n. V m
(8)
θ ai, θ ae - temperature of indoor and outdoor air
Based on the quantification of aerodynamic coefficients - Table 2 were processed values of
the air exchange rate for the reference room with volume V= 60 m3, i l,v =0,4.10-4
m3/(m.s.Pa0,67) and the joint length of 14 m.
From these values to calculate values of Ф v (W/K) and H v (W).
The impact of deployment and employment openings on each side of the building is shown
graphically in Figure 1. Values are shown for reference room located on the windward
alternative and side wall, with wind speeds of 15.5 m/s and varying the ratio of the size of the
holes located on the long side of the hole on the short side of the building (2:1, 3:1 and 4:1 ).
Table 2 and Figure 1 shows a higher proportion of openings on the windward side increases
the effect of these holes - total aerodynamic coefficient C p = C pe - C pi in these cases decreases
and thus reduces the intensity of the ventilation heat loss and consequently ventilation and
conversely.
Figure 2 and 3 shows a graphical representation of the ventilation heat loss Ф v and ventilation
heat loss coefficient H v on a particular critical day – 3rd January in test reference year with
consideration and without consideration of openings effect. The values are for a downwind
oriented room 1800, 3600.
Wind speed is between 4.9 m/s (at 23.00.) to 15.5 m /s (at 12.00)
900,00
Ventilation heat loss - W
800,00
700,00
600,00
500,00
400,00
300,00
200,00
100,00
0,00
Windward side
Cp= Cpe
2:01
Sidewall
3:01
4:01
Figure 1 - Variation of ventilation heat loss to the room oriented to windward and side wall in
varying proportions holes on each side
Figure 2 and 3 shows a graphical representation of the ventilation heat loss Ф v and ventilation
heat loss coefficient H v on a particular critical day – 3rd January in test reference year with
44
consideration and without consideration of openings effect. The values are for a downwind
oriented room 1800, 3600.
Wind speed is between 4.9 m/s (at 23.00.) to 15.5 m /s (at 12.00)
Figure 2 Comparison of ventilation heat losses for the critical day – 3rd January in test reference
year with considering and without considering the impact holes
Figure 3 Comparison of ventilation heat losses coefficient H v for critical day – 3rd January in test
reference year with considering and without considering the impact holes
45
5 CONCLUSION
The exact results of the air change rate and ventilation heat loss show that besides the basic
aerodynamic quantification, which reflects only the wind impact from the outer side of a
building (a direction, wind speed, ground-plan shape), acceptance of the air permeability of
the coating structures affecting the pressure conditions in the interior, plays an important role.
The interaction of pressure changes inside the building is, out of many operating factors,
influenced by the layout and orientation of openings towards the direction of the applied
wind, as well as their size and mutual ratios on every side of the building.
In spite of the fact that it is quite difficult to detect the wind character and its impact into the
boundary conditions of physical and technical dimensioning of the outer walls, the above
results suggest that each approach to reality provides the precision of the quantified results
Knowledge of this issue can be used to eliminate the adverse wind impacts in the early stages
of a design.
For the needs of design practice, the geometric scale of buildings should be extended with
more complex ground shapes in order to specify external aerodynamic coefficients along with
internal airflow modelling which is expressed by the internal aerodynamic coefficient.
The issue of more accurate quantification of the total aerodynamic coefficient value is
significantly manifested in the design of modern double transparent facade.
Použitá literatura
1.
2.
3.
4.
BIELEK M., BIELEK B.,: Interakcia budova – vietor v teórii energetickej potreby
budov, In: 6.vedecká konferencia Budova a energia 2005, Podbanské 12.14.10.2005, str. 64 – 69,
BULLOVÁ, I. Fyzikálna interakcia budova – vietor a jej aerodynamická
kvantifikácia In: Budownictvo o zoptymalizovanym potencjale energetycnym,
Czenstochowa, 2007, Poľsko, str. 17-22, ISBN 978–83–7193-357-8.
BIELEK M., ČERNÍK P., TAJMÍR M.,: Aerodynamika budov, ALFA Bratislava,
1999
STN 73 0540 1 – 4
Kontaktní údaje
Ing. Iveta Bullová, PhD.
Technické univerzita v Košiciach, Stavebná fakulta
Vysokoškolská 4, 040 01 Košice
Tel: 055 6024286
46
NEW APPROACHES TO CONSTRUCTION SITE DESIGNING
Mária Kozlovská, Jozef Čabala, Zuzana Struková
Abstract
The paper deals with construction site designing issues. The construction site facilities (CSF)
is the complex of all objects and equipments creating good conditions for building works
performance and organization as well as employees hygienic and social needs providing in
the building site. The legislation background of construction site designing as well as the
long-time tendency of Slovak construction companies approaches to the process of
construction site facilities designing are presented in the first part of the paper. Moreover,
there is presented the newest survey centred on the state of different construction sites in
Slovakia. The new approach to construction site designing, based on three-dimensional
parametric modelling, is mentioned in the second part of the paper. The theoretical bases for
3D parametric modelling of construction site and the proposal methodology of the 3D CSF
Allocation Model are there described and presented.
Key words: construction site, design, 3D parametric modelling
1
CONSTRUCTION SITE DESIGN - CURRENT KNOWLEDGE
Preparation of conditions for building performance in terms of the construction site designing
is one of important factors for successful and effective building realization. Site layout is
(Said and El-Rayes, 2010) considered as the space on site, which is available for temporary or
general construction equipment, material layouts, and flows of all resources involved in
adding to the end product. Good site layout planning assists (Tommelein et al., 1992) in
minimizing the travelling time and movement costs of plant, labor, and materials, activity
interference during construction work, and site accidents, and ensures that work on buildings
and other construction positions is not impeded by the thoughtless storage of materials on
these locations. The construction site facilities (CSF) is the complex of all objects and
equipments, which create good conditions for building works performance and organization
as well as employees hygienic and social needs providing in the building site. They create true
work environment for production process which result is the product – the building. It is
automatic, that the product quality and effectiveness is relative to the quality and effectiveness
of work conditions. For building industry is characteristic, that every “plant” (construction
site) is different, that is why is necessary to create (design) unless the construction plan also
the construction site plan for every building. The results of long research, realized in the years
1996-2008 on Civil Engineering Faculty TU Košice, show a tendency to approach Slovak
construction companies to the process of construction site facilities documentation.
always
sometimes
never
Fig.1 Answers to the question (%): Are you designing construction site facilities?
47
1.1 The legislation in field of the construction site designing
In the years before was legislation much more specific and in more details deals with methods
and principles of construction site designing. These principles were the part of regulations
dealing with the project preparation and documentation of the buildings (notice 105/1981,
notice 5/1987, notice 43/1990 – nowadays no one from them is valid). The actual regulation
453/2000 which deals with some dispositions of the building code only very briefly defines
the contents of the project documentation. According this one the project of construction site
organisation should be made in following composition:
1. Technical paper
2. Health and safety plan
3. Construction site situation (conception of the building site operation)
According the building code building office could consider the construction method and
advance, especially from point of:
- the building location,
- public demands protection, environmental protection against building activity effects,
health of people no participating on building protection, residential, communicational,
reminders zones and other reservations protection,
- assurance of appropriate work environment and work conditions for workers from
companies realizing the building.
1.2 The construction site solution structures
The part of the construction site situation elaboration is also the dimensioning (store places
measurements, communications length, sanitarian or office containers …) of the construction
site facilities in connexion with their location within the building site.
In general is needed to solve for the building site operation assurance:
▪ the building land occupation
▪ the building progress conception
▪ the building site entries and exits
▪ traffic ways for determining deliveries removal, disposal sites, dumping etc.
▪ road signs during building-up
▪ assurance of the water and electrical energy supply, line up of the building site objects
sewage, the building site drainage
▪ special arrangements for health and safety protection during building – up and manner of
their performance
▪ the building realization impact into environment and the method of elimination or
restriction of these impacts (fence, washing sets, toxic waste stocks, …)
▪ demands on the operating objects of the construction site (storing places, communications,
crane tracks, pre-mounting places, fence, construction site distributions, offices, …)
▪ demands on production objects of the building site (mortar and concrete production, steel
and forms preparation, …)
▪ demands on social and hygienic objects of the construction site (cloakrooms, washrooms,
toilets, rest rooms, drying rooms …).
1.3 Survey of construction site facilities in Slovakia
Solution for construction site operation is necessary to analyze from point of space structure
and time structure. For the building site accommodation is characteristic the change of space
solution in dependence on time structure. The building site changes during the building – up,
so as the demands on particular building processes assurance change.
48
Survey was processed in order to determine the status of equipment on construction sites in
Slovakia. Questionnaire surveyed data were divided into two main groups. First group information about the building structure included such data as type of construction, built-up
area, building space, indicative construction costs, the structural system, phase of construction
completion, number of workers on site or time of construction. The second group information
concerned to the construction site contained data about area and circuit of construction site,
method of determining the cost of construction site facilities (CSF), cost of CSF, project of
construction organization (containing situation with each construction site facilities). By
personal observation at all construction sites were surveyed types and numbers of objects
construction equipment (offices, dressing rooms, chemical toilets, washrooms, reception
rooms, storage containers, waste containers, fencing, ...).
For this paper are in Tab.1 selected data from ten buildings of apartment blocks or files of
apartment blocks. They are compiled descending by size of built-up space. The selection
represents structures with different built-up space and different number of stores.
chemical
toilets
toilet
containers
3
5
5
2
2
3
2
1
1
1
waste
containers
35
150
71
80
100
22
40
42
45
28
storage
containers
3256
6572
6548
4400
4133
16541
4104
4839
5960
1189
dressing
rooms
24
27
24
21
25
29
18
13
15
22
offices
4290
8990
8581
5600
5500
37430
5000
5580
7000
1520
number of
workers
1035
2418
2033
1200
1367
10890
896
741
1040
336
area for constr.
site facilities
[m2]
area of constr.
site [m2]
44796
38280
36060
28800
28700
27430
21504
18214
15600
7375
quantity of
percentage of
built-up area
[%]
built-up area
[m2]
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
built-up space
[m3]
apartment
blocks/files
Tab.1 Data about construction site facilities of apartment blocks/files (Source-authors)
3
8
4
3
10
3
6
2
2
2
3
5
2
2
3
2
2
2
4
3
4
4
3
6
4
2
3
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
-
gray shading - files of apartment blocks
On the basis of the data realized by the survey is possible to deduce the following statements:
- in all the cases, the area necessary for construction site development was sufficient, the
average percentage of built-up area was around 22%,
- the numbers of construction workers in site are various, it depends on the phase of building
process (from construction period point of view) in time of the survey realizing and on
building layout and opportunities for the workers setting into these places,
- the average area of dressing is 0,94 m2 per a worker (in 14,4 m2 area of a container) and
the variance is from 0,53 to 1,8 m2 – demanded area is 1,25 m2 per a worker and only two
building sites have met the requirement,
- the average number of the workers using one toilet is 16 (considering sanitary container
with four toilets) – in regard to demanded number of 15 workers per a toilet, the
requirement is met in average, the variance is from 4 to 28 workers per a toilet, the
requirement is at 5 building sites exceeded and at 5 building sites met,
- the waste containers are in all the building sites, this is absolutely positive.
49
2
THREE-DIMENSIONAL PARAMETRIC MODELING OF
CONSTRUCTION SITE FACILITIES
If the requirements of the construction work are changed during the progress of a construction
project, the site layout should be altered accordingly. Under this situation the construction site
layout planning problems should be regarded as dynamic problems (Ning et al., 2010).
Modern design methods of construction project which are based on three-dimensional
modeling systems (3D BIM) have a potential for faster and better proposal of structures or
modify existing solutions in terms of construction conditions implementation (Rynne, 2006).
Three-dimensional modeling systems to allow for construction site operation:
▪ interpretation of the real picture of the future construction site in virtual reality
▪ eliminate all conflicts before construction process starts
▪ allocate objects and facilities to construction site area
▪ simulation of on construction site activities
▪ view and drawing in any perspectives, cuts, details, etc.
In order to ensure the optimal solution construction site operations must be indiviadual
objects of CSF positioned in the space according to certain principles and requirements. The
concept of parametric modeling is derived from the project parameters that are modified
during the project simulation process. Parametric models are built from a set of mathematical
equations and must be based on actual or established project data.
2.1 Theoretical bases for 3D parametric modeling of construction site
3D view allows getting a more realistic vision not only about the conditions on construction
site, but also the context in relation to the surrounding of building. This view creates
preconditions for better perception of potential conflicts in terms of safety and health at work,
as well as protection of environment during the construction. 3D model provides a realistic
preview into an environment of construction site before the construction starts. Then we can
design the CSF so that the area where construction will take place processes to avoid
collisions on construction site. 3D environment allows seeing the actual proportions of
construction space, objects, facilities, whether the storage space needed for its
implementation, from all angles. In the digital spatial model is also possible the virtual walk
through the building site, in order to better understand also in terms the realization of the
building. 3D view of CSF allows to contractor of the construction as well:
▪ effective preparation of the necessary objects of CSF and their location due to space
limitations of the construction site,
▪ evaluation of their own capacity in relation needed for the smooth running of building
process,
▪ optimize the size and location of storage areas, or areas of manufacturing facilities,
▪ optimize the selection and location of cranes and construction machinery, in the context of
the conditions on the construction site,
▪ coordination of work due to health and safety protection,
▪ consideration of the construction site configuration and follow elimination or modification
necessary areas for development construction site operation,
▪ risks identification associated with the operation of construction site, etc.
Using 3D parametric modelling is necessary to define parameters of the spatial solutions of
construction site operation, their object models and connection between them. In 3D
modelling system plays a key role range of input parameters of object models that define the
possibilities and limitations its deployment.
50
2.2 Decisive spatial parameters for design of CSF in 3D environments
The model of CSF in a 3D environment is created by files of object models. Their placement
in construction site is depend on the spatial parameters of construction site. The object models
(objects of the realized buildings, objects of CSF, ...) are characterized mainly by their spatial
dimensions in 3D environment. The 3D environment allows "insert" to this models a number
of other information about them (description of usage, price, weight, ...). For modelling of
CSF in 3D environments is possible to define four basic spatial levels in space (Fig. 2):
i. Model of CSF (space, completing all objects and equipments, which create conditions for
building works performance)
ii. Object models of construction (models of individual construction objects, for example:
built-up structures, lines, access road, footpaths ...)
iii. Object models of CSF – CSFs object models (models of individual objects of
construction site facilities, for example: machinery, fencing of construction site,
communications, storage area, office, ...)
iv. Object models of surrounding the construction site (models of existing infrastructure
located outside of construction site, for example. surrounding objects, public roads, ...)
Fig.2: Concept of 3D object models of construction site (Source-authors)
The location of object models to CSF depends on spatial parameters of the construction site,
the spatial parameters of realized structures and the technological processes of construction
that predispose necessary CSFs objects. The selection and placement of CSFs objects of
construction site are based on certain principles. Especially when the spatial locations of CSFs
objects are placed should be seen of the location in relation to other objects in the whole
concept of the CSF. Some CSFs objects can be located from models of object construction
further away (dumping site, sanitary facilities, offices, etc.), others should be as close as
possible (material storage, work place, etc.) to the built-up structure.
In terms of solutions of spatial relationships on the construction site are particularly important
the following geometric characteristics of shape and size of these object models:
- whole construction site,
- realized building objects,
- storage areas,
- space for preparation and handling of products,
- machines (mobile and tower cranes, concrete pumps, ...),
- individual site facilities (roads, dressing room, offices, fencing, ....),
- and surrounding objects.
51
The design of CSF in a 3D environment required to use 3D object model database of CSFs
objects. (Fig.3). The object models of CSFs are placed in some database structure. This
structure is a strategy of selection object models of CSF into 3D system through the menu
from objects library. The individual object models can be parameterized in terms of 3D
dimensions, weight, purpose description, cost, etc. Selection of CSFs object models from the
database can be conducted by:
▪ searching - selection based on an intuitive way of searching,
▪ direct selection - selection according to certain characters (code, object type, ...),
▪ parametric selection - selection according to the specified input parameters.
2.3 The proposal methodology of the CSF Allocation Model
The following part describes a methodology for the parametric modeling spatial allocation of
CSFs objects in the 3D model of construction site operation – “3D CSF Allocation Model” based on the spatial parameters. The methodology is based on the modeling of virtual
solutions to the spatial structure of engineering production (Rudy, 2009). It is based on the
principles of pyramid construction technical interpretations (Fig. 3) of manufacturing systems
(the principle of bottom-up design).
3D
model
of CSF
Objects of
structures
+
Objects of CSF
Construction site
+
Site surroundings
Database of object models
3D model of construction
Fig.3: Model of technical interpretation pyramid construction of CSF 3D system
(Source-authors)
The goal of the 3D CSF Allocation Model methodology is layout - topology of CSFs object
models into 3D model of the construction site. Localization of CSFs objects by parametric
method is supported by knowledge-based decision-making based on the principles for the
selection and placement of construction site operation objects. The result should be a
processing of CSFs objects topology to minimize demands on construction site area. The
methodology starts with the selection of CSFs object model from database. Each CSFs object
model is defined by the operating space (gray mass in Fig. 4) which include a spatial model of
CSFs object and space needed for its functionality (opening of entrance gate, handling space
around pallets ...). For a machine with a working range (cranes, concrete pumps ...) the
working range of machines will be marked as a work space that will not restrict the location
of CSFs objects allocation. The topology of object model is supported by interactive spatial
allocation that responds to operational space of object and space of the construction site on
which is placed. The object models of construction (building, access road, parking ...) will be
presented on the construction site permanently occupied spaces. The exception will be their
released for the purpose of CSF objects location at the time when their realization according
52
to a schedule will still unnecessary. For solutions of the spatial allocation of CSFs objects are
important following geometrical characteristics:
▪ external dimensions of construction objects models and equipment of CSFs,
▪ minimum operating space of CSFs objects models,
▪ maximum size of construction site,
▪ vertical characteristics of construction site surface (which can limited the space for CSFs
objects location of).
The interactivity of CSFs object model location is based on color identification of the total
space of the CSF model. At the beginning of modeling the available of site surface, with the
exception of construction objects, is free (yellow color) for CSFs objects placing of (Fig. 4).
At their placing the green mass indicates sufficient space on the site. The red mass indicates a
lack of spatial of location and the impossibility location of CSFs object in the given space.
Fig.4: Identifying the location of CSFs object model in a 3D environment (Source-authors)
3D environment creates the possibility of a wide range of CSF spatial design solutions
(Fig.5). The result of allocation proposal is complex grouping of CSFs objects in space on
construction site in compliance with the principles of construction site operation design. This
design environment enables variant solutions of CSFs objects on construction site. The
individual CSFs object models can carry a variety of other information (price, time
availability, quantitative restrictions, maintenance requirements ...) they can be used for
following optimization of constructions site operations.
53
Fig.5: 3D model of construction site facilities (Source-authors)
3
CONCLUSION
The result of the survey presented in the paper mentions that even though almost a fifth of
buildings declared any construction site designing, in practice, the construction site facilities
present an unavoidable part of building production well-functioning and well operation. The
survey realized directly in situ (in building sites) mentioned that construction sites are
equipped by all main objects of construction site facilities. On the basis of the survey results,
it was possible to deduce the implications about the situation in general standards
performance from numbers of the objects point of view. In the second part of the paper are
presented the advantages of innovative approaches to construction site designing, based on
3D BIM models. The theoretical bases for 3D parametric modelling of construction site and
the proposal methodology of the 3D CSF Allocation Model are there described and presented.
Acknowledgements
The article presents a partial research result of project VEGA 1/0840/11 “Multi – dimensional
approaches supporting integrated design and management of construction projects“ and ITMS
26220120037 „Support of excellent integrated research centre of progressive building
construction, material and technology”.
Literature
1.
KOZLOVSKÁ, M. and STRUKOVÁ, Z. Opportunities and possibilities for more
effective construction site layout planning. In: Organization, Technology and
Management in Construction : 10th International Conference, Šibenik, University of
Zagreb, 2011 P. 1-15. - ISBN 978-953-7686-02-4
54
KOZLOVSKÁ, M. and ČABALA, J. Vizualizácia objektov zariadenia staveniska. In:
Realizácia a ekonomika stavieb, Trenčianske Teplice, Dom techniky, 2009. s 94-100.
ISBN 978-80-232-0301-1
3. KOVÁČ, J. and PEČOVSKÁ, K. Parametrické modelovanie montážnych prostriedkov
a systémov. Košice: TU, SjF, Transfer inovácií 5/2002.
4. MALLASI, Z. Identification, and visualization of construction activities’ workspace
conflicts utilizing 4D CAD/VR tools. Saudi Arabia: e-Design in Architecture KFUPM,
Dhahran,
December
2004.
http://www.iconviz.com/downloads/pub/MallasiASCAAD2005-pap.pdf
5. MA, Z., SHEN, Q, ZHANG, J. Application of 4D for dynamic site layout and
management of construction projects, Automation in Construction, Vol. 14 No. 3,
2005, pp 369-381.
6. NING, X., LAM, K.C., LAM, M.C.K. A decision-making system for construction site
layout planning, Automation in Construction, Vol.19 No.1, 2011, pp 55-65.
7. Parametric modeling. http://www.galorath.com/index.php/company/books/what-isparametric-modeling/
8. RYNNE, A. Parametric Modeling Basics [online]. University of Limerick. 2006.
http://www3.ul.ie/~rynnet/parametricmodellingbasics-solidworks.php
9. RUDY, V. Virtuálne riešenia priestorovej štruktúry strojárskych výrob. In: Transfer
inovácií. Č. 13 (2009), s. 231-235. - ISSN 1337-7094
10. SAID, H, EL-RAYES, K. Optimizing the planning of construction site security for
critical infrastructure projects, Automation in Construction, Vol. 19 No. 2, 2010, pp
221-234.
11. TOMMELEIN, I.D., LEVITT, R.E., HYES-ROTH, B. Site-layout modeling: how can
artificial intelligence help?, Journal of Construction Engineering and Management,
Vol. 118 No. 3, 1992, pp 595-611.
2.
Kontaktné údaje
prof. Ing. Mária Kozlovská, PhD., Ing. Jozef Čabala, Ing. Zuzana Struková, PhD.
Technická univerzita v Košiciach, Stavebná fakulta
Email: [email protected], [email protected], [email protected]
55
VLIV SÁLÁNÍ S OBLOHOU PŘI POSUZOVÁNÍ VĚTRANÉHO
STŘEŠNÍHO PLÁŠTĚ
INFLUENCE OF LONG WAVE RADIATION IN THE CALCULATION
OF DOUBLE LAYER ROOF
Sylvia Svobodová
Abstrakt
Hlavním tématem příspěvku je prověření výpočtového postupu pro posuzování větraných
střešních plášťů, uvedeného v normě ČSN 73 0540-4. Situace je modelována na dvouplášťové
šikmé střeše nad obytným interiérem. Poukazuje na důležitost vlivu sálání mezi střešním
pláštěm a oblohou. Za tímto účelem byly vymodelovány tři varianty střešního pláště, lišící se
použitou tepelnou izolací, v programu Mezera.
Klíčová slova: dvouplášťová střecha, větraná vzduchová vrstva, sálavý tepelný tok,
zkondenzovaná vodní pára, teplotní faktor vnitřního povrchu
Abstract
The main goal of this article is to verify calculation method used for assessment of ventilated
roofs declared by the Czech standard ČSN 73 0540-4. It is proved by a model of double-layer
roof enclosed to a residential interior. The model is designed in three variations, differing in
the material used for thermal insulation. Results are pointing on the importance of inclusion of
long wave radiation into calculations.
Key words: double-layer roof, ventilated roof, radiation heat flow rate, condensed water
vapour, temperature factor at the internal surface
1
ÚVOD
Předběžný návrh větraného střešního pláště z hlediska dimenzí vzduchové vrstvy a velikostí
větracích otvorů podléhá normě ČSN 73 1901. Po stránce tepelně technické nacházíme oporu
v normách ČSN 73 0540-1, 2, 3, 4. Pro návrh větrané vzduchové vrstvy tato norma [2] uvádí
jako hodnotící kritérium následující veličiny. Teplotní faktor vnitřního povrchu vnějšího
pláště, který ukazuje, zda na tomto povrchu nebude docházet ke kondenzaci vodní páry, a
vlhkost vzduchu v této vrstvě, která nesmí přesáhnout 90 % [2]. Teplotní faktor je ovlivněn
teplotou horního pláště a vlhkostí vzduchu v dutině. Teplota horního pláště je však ovlivněna
nejen teplotou venkovního vzduchu, ale také dalšími klimatickými podmínkami, např.
slunečním zářením, větrem proudícím po horním povrchu krytiny a také vlivem jasné oblohy.
Poslední zmíněný jev se ukazuje jako velmi důležitý. Takové podmínky nastávají vlivem
dlouhovlnné radiace při chladných jasných nocích, kdy ztrátový tok z povrchu konstrukce
směrem k obloze může dosáhnout až několik desítek W/m2. Významnou měrou ochlazuje
střešní plášť, a tím vznikají okrajové podmínky ještě méně příznivé, než které jsou uvedeny
v normě [3]. Proto také norma [2] doporučuje snížit součinitel prostupu tepla horního pláště
na hodnoty 1,5 – 2,7 W/(m2·K).
56
2
VÝPOČTOVÝ MODEL
2.1 Volba střešních skladeb
Byly zvoleny tři střešní skladby a dimenzovány dle ČSN 73 0540-2, tak aby vyhověly
podmínkám pro zimní období na požadované hodnoty. Jednotlivé varianty se liší použitou
tepelnou izolací:
1 – minerální vata
2 – dřevovláknitá izolace
3 – PIR
Podrobnější výpis všech skladeb je uveden v tab. 1. Se skladbou 1 se setkáváme v převážné
většině navrhovaných střešních plášťů rodinných a bytových domů. Je zde uvažováno s
parozábranou. Skladba 2 má tepelnou izolaci z dřevovláknité vaty, a to v kombinaci desek
s nižší a vyšší objemovou hmotností. Tato skladba nevyžaduje návrh parotěsné vrstvy.
Skladba 3 s PIR využívá jako jediná systému nadkrokevní izolace. Namísto klasické skládané
střešní krytiny byl navržen dřevěný záklop opatřený asfaltovou hydroizolací.
skladba 1
tloušťka [mm]
skladba 2
tloušťka [mm]
Sádrokarton
15
Sádrokarton
15
Dörken Delta-Fol WS
0,2
Uzavřená vzduch. dutina
50
Isover Rollino λ=0,042 W/(m·K)
50
Hofatex Therm λ=0,041 W/(m·K)
160
Isover Rollino λ=0,042 W/(m·K)
160
Hofatex UD λ=0,051 W/(m·K)
60
Dörken Delta-Vent S
0,3
Větranáná vzduch. dutina
40
Větraná vzduch. dutina
40
Dřevo měkké (tok kolmo k vl.)
25
25
Polyelast Extra Design
4
4
skladba 3
tloušťka [mm]
20
Bitagit
3,5
PIR λ=0,024 W/(m·K)
100
Bitagit
3,5
Větraná vzduch. dutina
40
25
4
Tab. 1 – Výpis skladeb
2.2 Parametry modelu
Následně byla navržena dimenze větrané vzduchové vrstvy ve střešním souvrství dle hodnot
doporučených v ČSN 73 1901. Posuzovaný střešní plášť má sklon 31°, délku střechy 5 m,
převýšení 3 m a tloušťku větrané vzduchové dutiny 40 mm. Šířka úseku byla zvolena
s ohledem na členění krokvemi, jejichž osová vzdálenost je 1 m. Šířka krokve je uvažována
100 mm, hodnocený úsek je tedy 0,9 m široký. Velikost přiváděcích a odváděcích otvorů
splňuje normová doporučení [5]. Krytí síťkou s 20 % zakrytím.
57
2.3 Metodika výpočtu
Návrh tloušťek tepelných izolací v jednotlivých skladbách byl prováděn v programu Teplo
2011, Svoboda software.
Každá z navržených tří skladeb byla výpočetně posouzena v počítačovém programu Mezera
2011, Svoboda software, a to pro dva stavy. V prvním případě byla zvolena nulová rychlost
proudění větru v okolní krajině, jedná se tedy o nejméně příznivou situaci. Tento postup je
v ČSN 73 0540 doporučen pro posuzování dvouplášťových konstrukcí. V druhém případě je
rychlost větru 1 m/s, odpovídající nechráněné poloze budovy.
Výpočty byly dále provedeny ve dvou dílčích variantách. První varianta postupuje klasickým
způsobem dle normových požadavků. Druhá zahrnuje vliv hustoty tepelného toku sáláním
mezi konstrukcí a oblohou. S pomocí této složky lze zohlednit nepříznivý vliv odnímání tepla
vnějšímu plášti dvouplášťové konstrukce vlivem výměny tepla sáláním mezi konstrukcí a
jasnou oblohou. Výsledkem pak může být významný pokles povrchových teplot na vnějším
plášti konstrukce a následný vznik kondenzace vodní páry.
V další fázi bylo dodatečně navrženo zateplení horního pláště minerální izolací, tak aby
nedocházelo ke kondenzaci na jeho spodní straně. Navržený horní plášť má hodnotu
součinitele prostupu tepla U = 3,36 W/(m2·K). V tab. 2 jsou přehledně uvedeny výsledky výše
popsaných variant, zda vyhoví, případně jakou tloušťkou tepelné izolace musíme opatřit horní
plášť, aby zde nekondenzovala vodní pára.
3
VYHODNOCENÍ
Skladba 1
0 m/s
1 m/s
klasický zp.
ANO
ANO
vliv sálání
NE
sálání
+
izolace h. pl.
(minerál.)
Skladba 2
0 m/s
1 m/s
klasický zp.
ANO
ANO
NE
vliv sálání
NE
ANO
ANO
25 mm
20 mm
sálání
+
izolace h. pl.
(dřevovlák.)
Skladba 3
0 m/s
1 m/s
klasický zp.
ANO
ANO
NE
vliv sálání
NE
NE
ANO
ANO
ANO
ANO
35 mm
20 mm
sálání
+
izolace h. pl.
30 mm
20 mm
(PIR)
Tab. 2 – Přehled výsledků
Z tab. 2 je patrné, že navržená dimenze větrané vzduchové vrstvy 40 mm je dle parametrů
hodnocených normou ČSN 73 0540-2 vyhovující. Těmi jsou teplotní faktor vnitřního povrchu
a relativní vlhkost vzduchu proudícího v otevřené vzduchové vrstvě, jehož hodnota nesmí
přesáhnout 90%.
Zahrneme-li vliv sálání mezi konstrukcí a oblohou, pak nevyhoví žádná z navrhovaných
skladeb. Teprve po částečném zateplení horního pláště se zamezí kondenzaci páry uvnitř
vzduchové vrstvy. Dle normového doporučení [2] by mělo stačit zateplení horního pláště na
hodnotu U = 1,5 – 2,7 W/(m2·K), což odpovídá přidání 3 – 15 mm minerální izolace ke
stávajícímu hornímu plášti. Tyto dimenze však nebyly dostačující, v tab. 2 jsou uvedeny
potřebné tloušťky u jednotlivých skladeb pro rychlosti větru 0 m/s a 1 m/s.
Při srovnání návrhových rychlostí v okolní krajině 0 m/s, tj. bezvětří a 1 m/s, odpovídající
nechráněné poloze budovy, vidíme, že pohyb vzduchu v mezeře snižuje riziko kondenzace
vodní páry na spodním líci horního pláště. Rychlost proudění větru je však velmi proměnlivá
veličina, proto je třeba počítat s nejhorší možností, tj. bezvětří. Na výsledky při okolní
58
rychlosti 1m/s je třeba pohlížet jen orientačně, pro srovnání jakých hodnot mohou počítané
veličiny nabývat.
Přestože jsou všechny tři varianty skladeb dimenzovány na požadované hodnoty dle normy
[2], [5], jsou zde rozdíly v tloušťce dodatečné izolace horního pláště. Je to pravděpodobně
způsobeno rozdílným difuzním odporem spodního pláště, tzn., že některé skladby jsou
schopné propustit více vodní páry z interiéru, než jiné.
4
ZÁVĚR
Hlavní hodnotící veličinou je riziko kondenzace vodní páry ve vzduchové vrstvě, a to na
spodním povrchu horního pláště [2]. Zhodnocením provedeného zkoumání vychází najevo
rozpor mezi výsledky získanými výpočtem se zahrnutím hustoty tepelného toku sáláním mezi
konstrukcí a oblohou a jeho zanedbáním. Střešní plášť nevyhoví dokonce ani při dodržení
doporučeného navýšení součinitele prostupu tepla horního pláště. Je-li výpočet prováděn
podle normových doporučení, získáme příznivější výsledky, které se však více liší od
reálného stavu. Tímto postupem vyhoví všechny posuzované skladby, dokonce i při bezvětří.
Ukazuje se, že sálání pláště s oblohou má neopomenutelný vliv. Největší význam má tento děj
během chladných jasných nocí, které jsou v jarním a podzimním období poměrně časté. Je
otázkou, zda by také tento jev neměl být parametrizován normovými požadavky.
1.
2.
3.
4.
5.
ČSN 73 0540-1 Tepelná ochrana budov – Část 1: Terminologie. Praha: Český
normalizační institut, 2005. 68 s
ČSN 73 0540-2 Tepelná ochrana budov – Část 2: Požadavky. Praha: Úřad pro
technickou normalizaci, metrologii a zkušebnictví, 2011. 44 s + změna Z1, 2012. 8 s
ČSN 73 0540-3 Tepelná ochrana budov – Část 3: Návrhové hodnoty veličin. Praha:
Český normalizační institut, 2005. 96 s
ČSN 73 0540-4 Tepelná ochrana budov – Část 4: Výpočtové metody. Praha: Český
normalizační institut, 2005. 60 s
ČSN 73 1901 Navrhování střech - Základní ustanovení. Praha: Úřad pro technickou
normalizaci, metrologii a zkušebnictví, 2011. 56 s + změna Z1, 2013. 8 s
Kontaktní údaje
Ing. Sylvia Svobodová
Vysoké učení technické v Brně, Fakulta stavební
Veveří 95, 602 00 Brno
Tel: 721 095 771
59
FOTOGRAMETRICKÉ MERANIA PRI ZAŤAŽOVACÍCH SKÚŠKACH
STAVEBNÝCH DIELCOV
PHOTOGRAMMETRIC MEASUREMENTS IN LOAD TESTS OF
STRUCTURAL COMPONENTS
Marián Marčiš, Marek Fraštia, Miroslava Chlepková
Abstrakt
Digitálna fotogrametria nachádza čoraz častejšie uplatnenie pri sledovaní zaťažovacích
skúšok rôznych druhov stavebných dielcov alebo celých konštrukcií. Jej hlavnými výhodami
sú pritom nízka časová náročnosť terénnych prác, vysoká dosiahnuteľná presnosť,
bezkontaktnosť a s ňou súvisiaca zvýšená bezpečnosť a napokon možnosť zaznamenať veľký
počet bodov v krátkom časovom intervale. Uvedený príspevok dokumentuje široké využitie
digitálnej fotogrametrie pri rôznych typoch zaťažovacích skúšok stavebných dielcov, ako
napr. sledovanie deformácií pri pôsobení vysokého tlaku, teploty alebo nárazov.
Klíčová slova: digitálna fotogrametria, zaťažovacia skúška, deformácie
Abstract
The digital photogrammetry is used very often while monitoring load tests of various types of
building components or entire structures. Its main advantages are low time costs of field
works, high attainable accuracy, contactless nature and the related increased security and,
finally, measurement of large number of points in a short period of time. The contribution
documents the wide use of digital photogrammetry for different types of load tests of
structural components, such as monitoring of deformations when exposed to high pressure,
temperature or impact.
Key words: digital photogrammetry, load test, deformation
1
DIGITÁLNA FOTOGRAMETRIA
Digitálna fotogrametria je založená na analytických vzťahoch vyjadrujúcich vzťah medzi
objektom v realite a tým istým objektom v rovine snímky. Pokiaľ je objekt zobrazený na
minimálne dvoch snímkach pod rôznym uhlom záberu, je možné zrekonštruovať jeho
priestorovú skladbu na základe identických bodov. Za dodržania špecifických podmienok,
ako napr. použitie skalibrovanej kamery, kódových cieľových značiek, optimálnej
konfigurácie stanovísk kamery voči objektu, dostatočného preurčenia každého bodu a pod. je
možné sa dopracovať k submilimetrovej presnosti vo vyhodnotení priestorovej polohy
pozorovaných bodov. Digitálna fotogrametria je tak okrem nízkej časovej náročnosti
terénnych prác a vysokej bezpečnosti merania výhodnou metódou aj z hľadiska finančných
nákladov - postačuje digitálna zrkadlovka, výkonný počítač a špecializovaný fotogrametrický
softvér. Využiteľnosť tejto technológie je v rámci príspevku rozdelená do troch praktických
aplikácií s rôznym prístupom k riešeniu úloh.
2
MERANIE DEFORMÁCIÍ POLOTUHÉHO PRÍPOJA
Využívanie polotuhých uzlov pri návrhu oceľových rámových konštrukcií je vo svete bežnou
praxou. Pre posúdenie odolnosti konštrukcií na seizmické účinky je veľmi dôležité vo výpočte
60
uvažovať s nelineárnymi materiálovými charakteristikami použitých elementov, aby bolo
možné sledovať postupný rozvoj plastických zón a vznik plastických kĺbov. Vďaka tomu je
možné stanoviť limitný stav konštrukcie tesne pred jej zlyhaním [1].
Cieľom fotogrametrických meraní bolo určenie deformácií špeciálneho typu polotuhého
prípoja (systém BAUMS, obr. 1), ktorý môže pri prenose veľkých vnútorných síl
(spôsobených napr. seizmickou udalosťou) nepriaznivo ovplyvniť stabilitu konštrukcie.
Hlavnými dôvodmi monitorovania deformácií stĺpu bolo porovnanie experimentu
s teoretickými výpočtami, stanovenie metodiky skúšania (nakoľko výsledky experimentu
môžu napomôcť s úpravou metodiky skúšania) a kalibrácia výpočtového modelu. Okrem
deformácií samotného polotuhého prípoja a deformácií pásnice stĺpa boli merané aj možné
deformácie celkovej konštrukcie skúšobného oceľového rámu s lismi a kotvenia stĺpa (obr. 2),
ktoré mali ostať nedeformované počas všetkých etáp zaťaženia.
Obr. 1 Rombická stužujúca sústava (vľavo) a detail kritickej oblasti "C" (vpravo) [1].
2.1 Prípravné práce
Na pozorovaný objekt boli na miesta pozorovania nalepené kruhové a kódové cieľové značky,
ktoré umožnili čiastočnú automatizáciu spracovania a zároveň dosiahnutie presnejších
výsledkov a to meraním so subpixelovou presnosťou 0,1pixela.
Obr. 2 Objekt experimentu (vľavo) a kódová cieľová značka (vpravo) [2].
V pozadí pozorovanej konštrukcie bola umiestnená sieť nezávislých vzťažných bodov,
ktorých poloha ostala nemenná počas celej zaťažovacej skúšky a tieto body slúžili pre
transformáciu jednotlivých zaťažovacích etáp merania do súradnicového systému základnej
etapy. Mierka fotogrametrického vyhodnotenia bola definovaná odmeraním vzdialenosti
medzi dvomi kódovými cieľovými značkami vzťažnej sústavy pomocou posuvného meradla
s presnosťou 0,1 mm.
Apriórnu presnosť fotogrametrického merania je možné za dodržania optimálnych
podmienok konvergentného snímkovania určiť podľa vzťahu [3]:
61
σ = M S ⋅ P ⋅σ '=
h
⋅ P ⋅ σ ' = GSD ⋅ σ '
f
(1)
kde M s je mierkové číslo snímky, P je veľkosť pixelu na CCD senzore, h je vzdialenosť
snímkovania, f je ohnisková vzdialenosť objektívu, GSD je veľkosť pixela na objekte a σ ′ je
presnosť určenia obrazových súradníc, ktorá sa pri automatickom meraní pohybuje v
rozmedzí 0.1 – 0.3 pixela. Použité fotografické vybavenie (Nikon D200 + objektív s
ohniskovou vzdialenosťou 20 mm) a predmetová vzdialenosť 1.5 m nám dáva apriórne
hodnoty presnosti 0.04 - 0.13mm, čo vyhovovalo kladeným požiadavkám.
Samotná zaťažovacia skúška sa skladala z dvoch častí:
• 1. časť pozostávala z postupného jednostranného zaťaženia do úrovne 240 kN/m2 a
potom späť na 0 kN/m2 v 6 etapách, pričom tlak bol vyvíjaný iba z pravej strany stĺpa,
• 2. časť pozostávala opäť z postupného jednostranného zaťaženia až do tlaku 240
kN/m2 a späť na 0 kN/m2, avšak s rozdelením na 16 etáp, pričom už po prvej časti
pozorované body vykazovali viditeľné nevratné deformácie.
2.2 Snímkovanie a spracovanie
V každej čiastkovej etape zaťaženia bolo po ustálení konštrukcie v rýchlom časovom slede
vyhotovených 5 snímok za použitia fotografického statívu a samospúšte pre minimalizáciu
otrasov a zmazu na snímkach. Polohu stanovísk kamery voči pozorovanému objektu je možné
vidieť na obr. 3.
Obr. 3 Približná poloha stanovísk kamery voči objektu počas snímkovania v každej etape
(vľavo) a definícia referenčného súradnicového systému (vpravo).
Zber obrazových dát v každej etape teda zabral maximálne 1 minútu, pričom poloha kamier
bola volená tak, aby každý vyhodnocovaný bod bol viditeľný minimálne na 4 snímkach.
Spracovanie snímok prebiehalo v softvéri PhotoModeler Scanner. Predpokladom kvalitného
vyhodnotenia snímok bola samozrejme kalibrácia použitej kamery, ktorá bola vykonaná na
kalibračnom a testovacom bodovom poli katedry geodézie na pôde Stavebnej fakulty STU v
Bratislave. PhotoModeler Scanner umožňuje spracovanie viacsnímkovej konvergentnej
fotogrametrie, ktorej veľkou výhodou je značná voľnosť vo voľbe polohy a orientácie kamery
voči objektu a zároveň vysoká miera preurčenia každého vyhodnocovaného bodu, vďaka
čomu je túto fotogrametrickú metódu možné považovať za najpresnejšiu.
Referenčný súradnicový systém bol volený tak, aby boli jednoducho interpretované
deformácie v pozdĺžnom a priečnom smere nosníka (obr. 3 vpravo).
Oceľový rám konštrukcie bol zostavený tak, aby zabezpečil stabilitu pozorovaného stĺpu a
prípoja v smere osi X, čiže nesmeli vybočiť mimo osi. Splnenie tejto podmienky bolo overené
fotogrametrickým meraním, z ktorého vyplynulo, že súbor pozorovaných bodov sa v tomto
62
smere vychýlil v priemere iba o 0.3 mm vplyvom vysokých tlakov, ktoré prebiehali v celej
konštrukcii.
Zároveň však z meraní vyplynulo, že oceľový rám a kotvenie stĺpa neboli stabilné v smere osi
Y a došlo k postupnému posunu opornej konštrukcie o 10 - 12 mm (obr. 4 vľavo).
Obr. 4 Body oceľového rámu vykazujúce posun 10 - 12 mm v smere osi Y (vľavo) a body s
najvyššou mierou deformácie v smere osi Z v oblasti styčníkového plechu (vpravo).
Z uvedeného vyplýva, že pre ďalšie návrhy konštrukcie na skúšobné testy bude potrebné
venovať zvýšenú pozornosť pevnejšej stabilizácii oceľového rámu. Toto nebolo možné zistiť
z tezometrických meraní, ktoré boli takisto realizované na pozorovanom objekte.
Najväčšie deformácie podrobných bodov stĺpa a polotuhého prípoja, vykazovali body v
mieste zvaru, kde bol predpoklad, že styčníkový plech sa bude zatláčať do relatívne mäkkej
pásnice stĺpa na jednej strane a vyťahovať na strane druhej [1]. Tento predpoklad bol
potvrdený najväčšími posunmi bodov v smere osi Z v tesnej blízkosti zvaru (obr. 5 vpravo).
Obr. 5 Posuny bodov v oblasti styčníkového plechu v smere osi Z voči základnej etape.
Priebeh deformácií spomenutých bodov je viditeľný na grafe na obr. 5 vpravo. Viditeľne
najväčšiu zmenu zaznamenali body 2014 a 2034 signalizované priamo na styčníkovom
plechu. Celkovo bolo pozorovaných 34 bodov, pričom v druhej epoche boli po dodatočnej
konzultácii pridané 4 doplnkové body, takže spolu narástol počet vyhodnocovaných bodov na
38.
3
MERANIE DEFORMÁCIÍ NEZOSILNENÉHO BETÓNOVÉHO
NOSNÍKA PO NÁRAZOVOM ZAŤAŽENÍ
Stanovenie odozvy betónových konštrukcií na účinky nárazového zaťaženia môže byť,
vzhľadom na krehké chovanie betónu, kľúčovým problémom pri ich návrhu, najmä v
súvislosti s rizikom náhleho zrútenia (kolapsu) konštrukcie. Zvýšené riziko predstavujú najmä
staršie konštrukcie, ktorých prvky, napr. stĺpy, majú nedostatočnú priečnu výstuž.
63
V rámci experimentu [2] boli rôzne druhy betónových nosníkov vystavené nárazovému
zaťaženiu spôsobenému pádom 118 kg závažia z výšky 0.18, 1.2, 1.5, 1.8 a 2.1 m. Na meranie
boli použité odporové tenzometre umiestnené na výstuži, induktívne priehybomery s voľným
jadrom a silomer v mieste dopadu závažia. Okrem týchto základných metód bola opäť použitá
aj metóda viacsnímkovej konvergentnej fotogrametrie. V tomto prípade však boli snímky
vyhotovené strednoformátovou digitálnou kamerou Phase One 645D s 33 Mpx digitálnou
stenou Leaf Aptus II-7. Apriórna presnosť vyhodnotených bodov je v tomto prípade pri
snímkovaní zo vzdialenosti 2 m podľa vzťahu (1) cca 0.03 - 0.10 mm. Kamerou bolo pre
každú etapu vyhotovených 5 snímok.
Obr. 6 Porušený nezosilnený nosník po nárazovom zaťažení v poslednej etape (vľavo) a
RAD-terč (vpravo).
Výsledkom fotogrametrického spracovania v softvéri PhotoModeler Scanner boli priestorové
súradnice jednotlivých cieľových značiek pre každú etapu zvlášť (obr. 7). Na samotnom
nosníku bolo vyhodnotených spolu 61 RAD terčov. Číslovanie cieľových značiek je viditeľné
na obr. 8.
Obr. 7 Konfigurácia stanovísk kamier počas snímkovania so znázornením vyhodnotených
bodov v jednej etape.
Obr. 8 Číslovanie pozorovaných bodov signalizovaných na betónovom nosníku pomocou tzv.
RAD terčov.
Na obr. 9 je možné vidieť posuny bodov 42 - 61 (spodný rad cieľových značiek) v smere osi
Z.
64
Obr. 9 Posuny pozorovaných bodov 42 - 61 v smere osi Z v jednotlivých etapách nárazového
zaťaženia [2].
Okrem použitia konvergentnej fotogrametrie a snímkovania strednoformátovou kamerou z
piatich rôznych stanovísk bola celá situácia sledovaná aj vysokorýchlostnou kamerou
Olympus zaznamenávajúcou 2000 snímok za sekundu. Z obrazových dát z jednej kamery by
síce nebolo možné vyhodnotiť priestorovú zmenu polohy bodov, pre tento prípad by však
každopádne postačovalo aj vyhodnotenie jednosnímkovej fotogrametrie v rámci 2sekundového videozáznamu a dopracovať sa tak k dynamike nárazu v rovine XZ. Počas
experimentu bolo totiž zistené, že tenzometre umiestnené na povrchu betónu a na niektorých
lamelách, napriek starostlivej ochrane a inštalácii, neboli funkčné. Použitie rôznych metód
merania pre určenie tých istých parametrov má preto vždy zmysel z hľadiska kontroly
výsledkov.
4
TESTOVANIE PROTIPOŽIARNEJ OCHRANY TUNELOVÉHO
OSTENIA
V súvislosti s problematikou pasívnej protipožiarnej ochrany tunelov sa v praxi používa
viacero testov na získanie čo najpresnejších informácii o správaní sa konštrukcie v prípade
požiaru. V rámci testu explozívneho odstreľovania povrchu betónu v špeciálnej peci teplote
až do 13000C je jedným zo skúmaných parametrov aj množstvo, resp. strata materiálu počas
simulovaného požiaru. Pasívna protipožiarna ochrana tvorí trvalú súčasť tunela a nevyžaduje
žiaden inicializačný systém v prípade požiaru. Pasívne systémy požiar nehasia, avšak sú
poslednou líniou ochrany a udržujú stabilitu konštrukcie tunela, aby mohol byť umožnený
bezpečný únik verejnosti a bezpečný prístup zásahových protipožiarnych jednotiek. Udržujú
v prevádzke vetracie systémy, ktoré sú oddelené od dopravnej časti vnútornými betónovými
konštrukciami. V prvom rade však pasívne systémy zabraňujú zrúteniu tunela a tým
katastrofálnym stratám na životoch, resp. majetku.
Základnou úlohou pasívnej protipožiarnej ochrany je [4]:
• minimalizovať rýchlosť stúpania teploty v betóne a oceľovej výstuži (ak sa tam
nachádza) a tým zachovanie celistvosti konštrukcie počas a po požiari,
• redukovať až eliminovať riziko explozívneho odstreľovania povrchu betónu
spôsobeného tlakom vodnej pary vo vnútri betónu.
Polypropylénovými vláknami modifikovaný betón vykazuje menšie povrchové odstreľovanie
betónu a v niektorých prípadoch sa odstreľovanie vôbec neprejaví. Práve tento typ
protipožiarnej ochrany bol predmetom testovania pri výstavbe tunela Airport Link
v austrálskom Brisbane pomocou testu explozívneho odstreľovania povrchu betónu.
Ukážka betónového panelu po teste je znázornená na obr. 10.
65
Obr. 10 Betónový panel po teste odstreľovania betónového ostenia
4.1 Digitálna fotogrametria pri odstreľovaní betónu
V priestoroch CSIRO (Commonwealth Scientific and Industrial Research Organisation),
Sydney bolo testovaných dokopy 16 vzorových panelov s rozmermi 2600mm x 1000mm x
250mm, ktoré sa líšili zložením betónovej zmesi, ale hlavne percentuálnym podielom
polypropylénových vlákien, ktoré slúžia ako anti-odstreľovacia zložka betónu. Cieľom
merania bolo určiť geometriu daných panelov pred a po vykonaní testu, vytvorené digitálne
modely navzájom porovnať a určiť hĺbku odstreleného materiálu. Fotogrametrické meranie
bolo vykonané s použitím digitálnej zrkadlovky Canon 500D a opäť bol použitý
fotogrametrický softvér Photomodeler Scanner (submilimetrová presnosť pri daných
podmienkach).
Samotné meranie sa vykonávalo v dvoch fázach, a to pred a po vykonaní testu. Pomocou
žeriavu bol každý panel individuálne umiestnený tak, aby bolo možné nasnímať plochu
určenú na testovanie. Do danej plochy boli následne nainštalované špeciálne geodetické
klince odolné voči vysokej teplote s dĺžkou min. 8cm (predpokladaná maximálna hodnota
straty materiálu bola do 5 cm), ktoré slúžili na zabezpečenie identického referenčného
systému pred a po vykonaní testu. Ich rozmiestnenie je znázornené na obr. 11.
Obr. 11 Rozmiestnenie geodetických klincov na betónovom paneli
Pre urýchlenie spracovania boli opäť použité aj kódové cieľové značky.
4.2 Spracovanie technológiou obrazového skenovania
Okrem selektívneho bodového vyhodnotenia bola v rámci tejto aplikácie využitá aj veľmi
aktuálna technológia obrazového skenovania, ktorá umožňuje na základe obrazovej korelácie
a epipolárnej geometrie vyprodukovať z dvojice snímok mračno bodov - obdobný výstup, aký
je dosiahnuteľný pomocou finančne veľmi náročných terestrických laserových skenerov.
Práve softvér PhotoModeler Scanner totiž vďaka modulu DSM (Dense Surface Modeling)
umožňuje automatizované generovanie mračien bodov z párov orientovaných snímok hlavnou podmienkou je, aby snímaný povrch disponoval nepravidelnou náhodnou textúrou,
pričom práve s textúrami stavebných materiálov ako sú betón, kameň a pod. je možné
dosiahnuť najlepšie výsledky.
Postupne teda boli generované 3D mračná bodov záujmových oblastí s krokom 10 x 10 mm a
z nich boli následne vytvárané TIN modely.
66
Obr. 12 TIN model betónového panela po teste
4.3 Interpretácia výsledkov
Digitálne modely povrchu „pred” a „po“ teste boli exportované do .dxf a .txt výmenného
formátu a následne spracované pomocou grafického softvéru AutoCAd Civil 3D 2009. Údaje
z merania po teste boli ovplyvnené priehybom, ktorý nastal v dôsledku zahriatia betónového
panelu a zároveň pôsobením jeho vlastnej tiaže. Údaje o priehybe boli poskytnuté priamo od
vykonávateľa testu a zároveň skontrolované na základe meranej zmeny polohy vlícovacích
bodov 2, 5 a 7. Priehyby boli numericky odstránené pomocou softvéru Terramodel.
Cieľom bolo určenie množstva odstreleného materiálu po celej exponovanej ploche vzorky.
Keďže digitálne modely „pred“ a „po“ teste boli v identickom súradnicovom systéme vďaka
vlícovacím bodom, na prezentáciu požadovaných výsledkov slúžil rozdielový model týchto
dvoch povrchov.
Obr. 13 Farebné znázornenie úbytku materiálu na rozdielovom modeli
5
ZÁVER
Či už sa jedná o deformácie stavebných dielcov spôsobené postupným zvyšovaním tlaku,
nárazovým zaťažením alebo vysokou teplotou, digitálna fotogrametria umožňuje v krátkom
čase získať priestorové súradnice pozorovaných bodov so submilimetrovou presnosťou.
Vďaka bezkontaktnosti je táto metóda zároveň aj veľmi bezpečná a s použitým vybavením aj
pomerne finančne nenáročná. Čiastočnou nevýhodou môže byť časová náročnosť
spracovania, avšak súčasná technológia umožňuje vysokú mieru automatizácie celého procesu
merania a v špecializovaných riešeniach je možné dopracovať sa k požadovaným výsledkom
online priamo počas zaťažovacieho testu.
Pri meraní nepravidelných povrchov sa opäť javí fotogrametria oproti terestrickým
geodetickým metódam vo výhode, nakoľko na základe snímok je možné v post-processingu
zvoliť taký raster meraného mračna bodov, aby vystihoval a zachytával všetky detaily na
meranom povrchu a to až po raster s krokom rovným predmetovej veľkosti obrazového
elementu, čo je časť meraného povrchu, ktorá sa na snímke zobrazí ako jeden pixel.
67
1.
2.
3.
4.
LANG, T.: Analysis of cyklic loaded diagonal-to-column joint. In Juniorstav 2011:
13. Odborná konference doktorského studia. Brno, VUT, 4.2.2011. Brno: Vysoké
učení technické v Brně - Fakulta stavební, 2011, ISBN 978-80-214-4232-0.
MARČIŠ, M.; FRAŠTIA, M.: Meranie deformácií polotuhého prípoja metódou
konvergentnej fotogrametrie. In Zkoušení a jakost ve stavebnictví 2013, 1. - 2. října
2013, Fakulta stavební VUT v Brně, Vysoké učení technické v Brně, ISBN 978-80214-4777-6.
FRAŠTIA, Marek. Kalibrácia a testovanie digitálnych kamier pre aplikácie blízkej
fotogrametrie: Edícia vedeckých prác. Zošit č.52. Bratislava: STU v Bratislave Svf.
2008. 114s. ISBN 978-80-2272812-6.
www.efnarc.org. Specification and guidelines for testing of passive fire protection
for concrete tunnels linings, March 2006.
Kontaktní údaje
Ing. Marián Marčiš, PhD.
Slovenská technická univerzita v Bratislave, Stavebná fakulta, Katedra geodézie
Radlinského 11, 813 68 Bratislava
Tel: +421 2 59274 427
Ing. Marek Fraštia, PhD.
Slovenská technická univerzita v Bratislave, Stavebná fakulta, Katedra geodézie
Tel: +421 2 59274 398
Ing. Miroslava Chlepková, PhD.
Pamiatkový úrad SR, Oddelenie grafickej dokumentácie,
Cesta na červený most 6, 814 06 Bratislava,
Tel: +421 2 20464 308
68
METHODOLOGY OF THE OPTIMAL DESIGN OF CONSTRUCTION
OF TERRACED FAMILY HOUSES
Renáta Bašková, Marek Krajňák, Ján Slivka
Abstract
The terraced construction of large amounts of the terraced family houses belongs to
constructions with an uniform distribution of larger volume of different types of building
structures in area. Initial conditions are created for smooth, uniform and rhythmic deployment
of the production capacity, characteristic for the chain method of construction. The paper
presents a methodology for variant design of construction of the terraced family houses,
stages 2A and 2B of construction: Panorama - residential complex Košice. Aim of the
proposal and assessment of variants of timetable was to find the optimal progress of
construction in terms of design and technological solutions, construction time and resource
utilization.
Key words: chain construction method, coherence construction projects, spatial work zone,
construction process, family houses,
1
CONSTRUCTION METHODS OF THE TERRACED FAMILY
HOUSES
The row construction is execution of usefully-spatial arrangement of functional consecutive
family homes mostly the same features, not excluding their architectural diversity. At
construction large amounts of terraced of family houses can find application parallel, gradual
and chain method of construction. Choosing the appropriate method does not affect the
required deadline of construction only, but also the number of participants in the construction
and relations between them.
More extensive construction of the terraced family houses, which investor is a development
company, its design and technological solution usually creates favorable conditions for the
utilization a benefits, which the chain organization of works provide.
The basic condition for the chain organization of construction in practice is that the scope of
work for the implementation of building structures allows sharing production space for
multiple spatial work zones with parallel developing a work queues. An application of the
chain method requires:

Must be available batch of products, i.e. approximately the same type and scope.

Proposal for optimal division of labor between specialized teams in the flow and
design of technologically appropriate sequence of processes (Christodoulou et al.,
2010).

Each team (platoon, team) makes by their job a free working front for following
platoon, while labour collectives do not interfere with each other, i.e. must not meet
in one section of building (spatial work zone). Substitution of crews (processes) on
spatial work zone is subject to some coordinated rhythm.

Understanding and willingness on the part of managers, i.e. from construction
managers, site managers and their assistants, subject deployment of generating
capacity in the construction to the planned work in rhythmic time (Fathi and Afshar,
2008; Kozlovská and Struková, 2011-a).
69
Plan for security conditions of the chain organization of construction is addressed within
construction and technological preparation of construction (Kozlovská et all., 2010-a).
Current construction planning can be divided into the following operations:

Structurally and technologically appropriate objects are divided into approximately
equal parts - spatial work zone (created the series).

Total (complex) work process is divided into partial, staged and object processes
according to technological nature.

To the whole production will be introduced mandatory rhythm with time-modulated
activities of crews on individual spatial work zone.
The organization works subject to a predetermined procedure for platoons of partial streams
in the area and it is important to also smooth and steady supply of construction by
construction materials (Hiyassat, 2001; Kozlovská and Struková, 2011-b).
2
FORMULATION OF THE OBJECTIVES AND METHODOLOGY
OF SOLUTION CONSTRUCTION TIMETABLE OF THE
TERRACED FAMILY HOUSES
The aim was to propose different variations of the time during the current realization of
construction terraced of family houses of construction stages 2A and 2B Panorama residential complex Košice. Based on a comparison of selected variant solutions to the real
course of construction and construction milestones set by the developer, to recommend the
optimum variant in terms of construction time and resource deployment.
The methodology of solving consists of the following steps:
3
1)
Analysis of the construction - Panorama - residential complex, Košice – stages of
2A and 2B from the design, spatial and technological point of view. Specification
and then providing documents and information from the implementation of real
construction.
2)
Analysis of input for variant solution of chain organization of construction
Panorama - residential complex.
3)
Assessment of optimal solutions proposed compared with the real construction.
CASE STUDY – THE CHAIN METHOD OF CONSTRUCTION OF
ROW FAMILY HOMES
The case study brings to light an issue of chain method of construction of row family homes
2A and 2B phase construction: Panorama - residential complex, Košice.
3.1 Description of construction Panorama - residential complex, phase 2A and 2B
Construction phase 2A and 2B includes 56 row family homes, where from structural point of
view represented by three types of houses (A 121, B 131 and C 141).
70
Figure 1: Construction phases: Panorama - residential complex (Source: http://www.domy-kosice.sk
Family homes all three types are mostly the same structural character with the exception of
some construction details. Objects of the family houses based on the foundation strips and
footings from unreinforced concrete in combination with formwork blocks. Concrete ground
layer of floors on terrain is reinforced with mesh. External bearing masonry include
translations of holes is made from ceramic blocks. Masonry, attics and partitions are finished
by reinforced concrete wreaths. Pillars under shelter to the family house are from the wood.
The horizontal support structure and internal staircase is made from monolithic reinforced
concrete. Structure of the roof structure of object above second floor is a wooden shed with a
small inclination with PVC covering.
Figure 2: Three types of row family houses - A 121, B 131 and C 141 (Source: http://www.domy-kosice.sk)
For design of chain construction method and for subsequent consideration of variants
optimality compared with the actual construction were necessary following documents and
information:






the situation of construction;
drawing documentation of typical houses A 121, B 131 and C 141;
report and assessment of processes for type houses;
milestones (beginning and finish) of construction determined by developer, for stage
2A from 11/2011 to 5/2013, and for stage 2B from 8/2012 to 11/2013;
timetable for the actual implementation of the works, where the realization of the
family houses of construction stage 2A and 2B was conducted between November
2011 and the expected end of construction was planned for August 2013;
number of workers on site (information from construction), "in the top" working on
construction about 130 employees (as indicated max. fig 4, 5 and 6).
71
3.2 Variant solution of the chain organization of construction: Panorama - residential
complex
In designing of chain organization of construction of terraced family houses is essentially a
searching appropriate answers to three basic questions about the spatial, technological and
timing allocation of construction (Hegazy, 1999):
1. What will the division of 56 terraced family houses at about the same (normal) spatial
work zones, i.e. what is a normal spatial work zone and what is the procedure for
assigning of spatial work zone to construction in time and space of structure?
2. What will division of the complex work process according to technological nature to
split, multistage and object processes?
3. What is the time of duration of the work of crews on spatial work zones and at what
time intervals will follow crews assigned to the stream?
Particular appraisal of time, technological well as spatial parameters of the construction
process represents a variant input for proposal of timetable construction. In search of answers
to the questions may have different parameters interacting values.
3.2.1
The normal spatial work zone and process of assigning of family houses to
construction
Normal spatial work zone could be the spatial part of the house, a house or a spatial work
zone composed of the multiple family houses. In determining the size of the spatial work
zones was taken into account the scope of work, as well as the recommendation that one
should have shot about from 200 m2 to 600 m2 ground area of objects. The spatial work zone
was adjusted to 5-working days tact, wherein said spatial division on spatial work zone
satisfying the 2-week tact. In the particular case of the construction was divided into 15
spatial work zones where one spatial work zone consists of 4 buildings A 121, B 131, or 3
houses of type C 141. Processes of assigning of family houses take into account both type of
objects and their location in space of construction.
3.2.2
Design of the partial streams during of realization of family houses
Proposal of the technological structure for normal spatial work zone, i.e. number and source
evaluation partial streams, based on analysis of construction processes: from report and
assessment and specification measurement and their technological nature and mutual
conditionality so that previous partial stream created workspace for crew of the following
partial stream.
A hierarchy of partial streams preceded by detailed analysis of specification measurement
processes different types of houses, including their labor intensity (El-Rayes and Jun, 2009).
Labor input processes for normal spatial work zone were all designed to meet all three types
of houses. For normal spatial work zone was proposed composition of crews working substreams for the duration of a balanced work in different spatial work zones.
Standards
hours per 3
houses
Technologica
l break
Standards
hours per 1
house
18,05
5,21
94,10
282,3
7
280
100,82
5
m3
14,27
1,53
21,84
65,52
2
80
81,90
5
Tension
Number of
workers
Tact
Standards
hours per
measure unit
m3
Work hours
Quantity
Excavations and
horizontal wiring
Foundations,
concrete slab
Measure unit
Activities
Standard for 1 spatial work zone
5
72
Vertical structures
1st floor
m3
25,08
6,04
151,37
454,11
12
480
94,61
5
Concrete beams
m3
40,00
1,47
58,77
176,31
5
200
88,16
5
5
Concrete ceiling
3
m
11,13
11,38
126,64
379,92
10
400
94,98
5
5
Vertical structures
2nd floor
m3
77,67
2,48
192,37
577,22
15
600
96,19
5
Staircase
m3
16,45
2,48
40,86
122,58
3
120
102,15
5
Roof
m2
84,53
1,68
142
426
11
440
96,82
5
Partitions
m3
55,65
1,45
80,63
241,89
6
240
100,79
5
Water and sewer
wiring
m
42,50
2,34
99,36
298,08
8
320
93,15
5
Electricity wiring
m
45,00
3,54
21,54
64,62
2
80
80,78
5
Installation of doors
and windows
m2
22,20
2,36
52,29
156,87
4
160
98,04
5
Plasters
2
m
365,97
0,53
192,23
576,69
14
560
102,98
5
Facade insulation
m2
178,29
2,07
369,67
1109,01
7
1120
99,02
20
Insulation of floors
and screeds
Gutters and window
sills
m2
147,86
0,59
86,58
259,74
7
280
92,76
5
2
m
33,6
0,98
33,07
99,21
3
120
82,68
5
Plasterboard ceilings
m2
76,10
0,50
74,67
224,01
6
240
93,34
5
2
365,97
0,53
192,23
576,69
15
600
96,12
5
Painting and
cleaning
m
5
Table 1: Technological standard: partial streams with balancing of the duration of the tact = 5 days, where the
normal spatial work zone consists of four houses type A 121, B 131, or 3 houses of type C 141(Source: authors)
Construction stage
HSS – row lower structure
HVS – row upper structure
ZS – roofing
F – facade
D – finishing works
Number of the partial streams for tact:
5 turns
2 partial streams
1 fictitious stream
5 partial streams
2 fictitious streams
1 partial stream
4 crews working with double rhythm
with the tact of 20 days
9 partial streams
Number of the partial streams for tact:
10 turns
2 partial streams
4 partial streams
1 fictitious stream
1 partial stream
2 crews working with double rhythm
with the tact of 20 days
6 partial streams
Table 2: Number of the partial streams in the normal spatial work zone (Source: authors)
At the final design of a hierarchy of processes/streams was object process divided into 5
construction stages, which in turn were divided into sub-streams corresponding to the one
specialized work crews and fictitious streams at the time of ongoing technological break.
Sequence, number and composition of specialized crews for partial processes/streams have
been adjusted in the normal spatial work zone and the selected tact 5 and 10 turns.
3.2.3
Design of the partial streams during of realization of family houses
Tact (duration of work crews in each of the spatial work zones) is mostly multiple of across
all turn, and can take values from one turn already, but the practical experience of the past is
an appropriate tact at least 2 or 3 days, practice prefers one week (5 or 6 days when the
weekend can be used for smaller delays in production), or longer, for example, two weeks (10
or 12 days). Some crews can work with so-called "double rhythm" (partial stream consists of
n crews, taking in every spatial work zone refrain from n-fold tact). Work can be designed
"speed-line" in a way that is crews embarking on spatial work zone immediately after leaving
of the spatial work zone by the previous crew (step of flow is equal the tact), or spatial work
zone to be taken up after a delay (step of stream is greater than the tact, which is usually
chosen as integer multiples of the tact).
In this concretely case, the proposed two variants for the duration of the work crews in one
73
spatial work zone: tact = 1 week (5 turns) and tact = 2-weeks (10 turns).
Both variants tact were used for stream-speed method of construction, which is step equal to
the tact. The third variant counts with tact one week following the onset of crews with a
weekly interval, i.e. step of partial streams is equal to twice the tact (step of = 2 weeks).
3.3 Assessment of optimality of the proposed solution compared with the actual
construction
Chain method of construction requires a thorough structural and technological preparation
with the solution of a time sequence of specialized work crews in the area of structure
(Kozlovská et all., 2010-b; Kozlovská, 2007). On the other hand mathematical foundations of
chain method allow for a relatively short period of time to evaluate selected characteristics of
construction (construction period, the intensity of the deployment and use of resources, etc.)
For several variants with different input conditions, either by calculation or by graphical
display during the construction of space-time graphs or histograms selected sources. Chain
method of construction is a means of bringing in the organization of construction "order"
which can ultimately result in lower construction costs.
Figure 3: Cyklogram processed in relative calendar (tact = 5 turns) (Source: authors) Legend: On the x-axis is
the time of construction in weeks, and on the y-axis is 15 spatial work zones of 2A and 2B phases divided into
specific family houses of this type.
At Figure 3 is a time-spatial graph course of construction of 56 residential houses of the
complex Panorama, processed in the relative calendar for tact: 5 turns, which served as the
primary basis for the processing of three variants of construction schedule.
Variants are compared with one another on the overall construction time (work schedule for
the real construction and 3 variants) and the need for labor resources (histogram, see Fig. 4, 5
and 6).
Real construction
Variant 1.
Variant 2.
Variant 3.
Start of
construction
11/2011
10/2011
10/2011
10/2011
End of
construction
8/2013
11/2012
2/2013
9/2013
The construction
period
21 months
14 months
17 months
24 months
Maximum number
of workers
130 workers
116 workers
75 workers
118 workers
Table 3: Comparison of all variants versus real construction (Source: authors)
In the schedules (real construction and proposed options 1, 2 and 3) are taken into account
74
specified milestones (start of construction consistent with the schedule) and the winter season,
at which time it was interrupted several partial streams with "wet process" (row lower
structure, row upper structure and facade modifications).
max. 116 workers
Figure 4: Histogram of workers for variant 1 (Source: authors)
max. 75 workers
max. 118 workers
75
Chain method of construction is a means of bringing in the organization of construction
"order" which can ultimately result in lower construction costs. Using of benefits of the chain
organization of construction is also possible in the implementation of architecturally attractive
and creative structures.
4
CONCLUSION
Chain method itself does not guarantee a smooth running of construction. Even the design of
the time course of the work by a chain method may be useful to examine several variants
where the variables deal with the solution the division of construction to spatial work zone
(number, size of spatial work zone and placement procedure of the construction), number,
rank and resource assessment of partial streams and the time interval between the onset of
successive partial processes into spatial work zones. Variants may reflect the availability of
labor and material resources, different working fund (work over the weekend or in multiple
turns) and so on.
Acknowledgements
Contribution was written within the implementation of the project VEGA 1/0840/11
Multidimensional approaches to support integrated design and management of construction
projects.
References
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CHRISTODOULOU, S. E. et al. (2010) Minimum moment method for resource
leveling using entropy maximization. Journal of Construction Engineering and
management, vol. 136, 2010, No. 5, p. 518-527.
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EL-RAYES, K., JUN, D. H. (2009), Optimizing resource leveling in construction
projects. Journal of Construction Engineering and management, vol. 135, 2009, No.
11, p. 1172-1180.
3.
FATHI, H., AFSHAR, A. (2008) Multiple resource constraint time – cost- resource
optimization using genetic algorithm. In: First international conference on
construction in developing countries, August 4.-5. 2008. Karachi, Pakistan. p. 42-50.
4.
HEGAZY, T. (1999) Optimization of resource allocation and leveling using genetic
algorithms. Journal of Construction Engineering and management, vol. 125, 1999,
No. 3, p. 167-175.
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HIYASSAT, M. A. S. (2001). Applying modified minimum moment method to
multiple resource leveling. Journal of Construction Engineering and management,
vol. 127, 2001, No. 3, p. 192-198.
6.
KOZLOVSKÁ, M. (2007). Prístupy k realizácii stavieb s krátkymi termínmi
výstavby. In: Konstrukce. Vol. 6, no. 2 (2007), p. 78-80. - ISSN 1213-8762
7.
KOZLOVSKÁ, M., SABOL, L. (2010-a). Innovation approaches to building project
preparation and realization. In: Czasopismo techniczne. Vol. 107, No. 2, 2010.
S.213-221. ISSN 0011-4561.
8.
KOZLOVSKÁ, M., STRUKOVÁ Z., TAŽIKOVÁ A. (2010-b) Access to
construction time objectiveness. In: Organisation, Technology and Management in
Construction: An International Journal. Vol. 2, No. 2 (2010), p. 200-206. - ISSN
1847-5450
9.
KOZLOVSKÁ, M., STRUKOVÁ, Z. (2011-a). Environmental and safety education
in building industry through unconventional teaching techniques. In: SGEM 2011 :
11th International Multidisciplinary Scientific GeoConference : conference
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proceedings, Bulgaria, Albena. - Sofia : STEF92 Technology Ltd., 2011. S.
1249.1256. ISSN 1314-2704.
KOZLOVSKÁ, M., STRUKOVÁ, Z. (2011-b). Opportunities and possibilities for
more effective construction site layout planning. In: Organization, Technology and
Management in Construction : 10th International Conference : 07 - 10 September
2011, Šibenik, Croatia. - Zagreb : University of Zagreb, 2011 P. 1-15. - ISBN 978953-7686-02-4
SON, J., MATTILA, K. G. (2004). Binary resource leveling model: Activity splitting
allowed. Journal of Construction Engineering and management, vol. 130, 2004, No.
12, p. 887-894.
Contact information
doc. Ing. Renáta Bašková, PhD.
Technical University of Košice, Slovakia
Institute of Civil Engineering Technology and Management, Faculty of Civil Engineering,
Tel: +421 055 602 4379
E-mail: [email protected]
Ing. Marek Krajňák
Technical University of Košice, Slovakia
Institute of Civil Engineering Technology and Management, Faculty of Civil Engineering
Tel: +421 055 602 4385
77
PROGRESIVE DATA PROCESSING FOR BUILDING
RECONSTRUCTION
Tibor Šoltés, Mária Kozlovská
Abstract
Building reconstruction or renovation is complex process. Calculate volumes, quantities and
remodel surfaces especially in historical building sector is very difficult. Laser scanning
method improves the documentation data collection and provides a basis for creating a
building information model. This model can be used for design of building reconstruction.
The article deals with integration of progressive tools such as laser to model technology, in
the category of building reconstruction. The aim is to show the possibilities and advantages of
the information model in the area of building refurbishment.
Key words: reconstruction, data, laser
1
INTRODUCTION
Building Information modeling has become the main instrument for coordinating the data in
the project. Its advantages can be applied also in the process of building renovation.
Reconstruction is the specific industry that requires intensive preparation. Consuming
preparation is one of the barriers to implement Building Information Modeling in the recovery
process. This situation could change by adopting new technologies such as laser scanning that
will facilitate data collection. The original construction documentation is often incomplete or
completely lost. Survey the building state is the basis for the final project. This is especially
true for historic buildings where surveying takes up most of the time. Problems are especially
in complicated details of facades and roofs. Documenting the state with laser technology
significantly improves quality of work documentation. The documentation is then processed
in a virtual environment. This environment facilitates the designer's vision of construction and
it can be presented via 3D printers.
2
DATA PROCESSING - LASER SCAN
3D laser scanning used in conjunction with other methods of recordation, including highresolution photography, and visual inspection of the building’s materials. Full sets of 2D plan
and elevation drawings are often required and the scan data itself is increasingly provided as
part of the client deliverable. High-definition surveys are also used to precisely capture
existing geometry for heritage buildings that are to be meticulously taken down and then rebuilt in another location. Scanning is a great tool for brick-for-brick, panel-for-panel matching
of the original building with the re-built building. Scanning is used to help analyze structural
damage or even cosmetic damage, such as older buildings that have begun to shift and sag
over time. Where there has been a collapse or other serious damage, scanning is used to
accurately assess the structural damage so as to enable accurate repairs. A corollary of this
application is to use scanning to capture an accurate “before” geometric snapshot of a
building prior to any construction being completed on the building. In this way, if a building
is or is not damaged during construction, the contractor or building owner will have a record
that can be used to quickly resolve disputes such as, “Hey, that exterior crack wasn’t there
before!” or “I think you altered the shape of my building when you installed the underground
garage!” Scanning provides inexpensive dispute resolution insurance. Monitoring
deformation and building movement [1].
78
Building survey
From a given position the object to be digitized, the scanner projects a low-power, nondamaging laser light upon a section of the object’s surface. Each point of the surface touched
by the laser light is captured by a CCD camera integrated into the scanner, and both the X, Y,
Z coordinates and the laser light intensity of each of these points are recorded in the memory
of the computer controlling the scanner. This operation is repeated thousands of times each
second and generates a file containing a large amount of point data of the scanned surface.
This file, displayed on the computer screen, shows the 3D shape of the scanned surface. Thus,
the operation of creating sequential overlapping images from multiple points of view on the
surface of the object is carried out until the entire surface of the object is covered. Individual
3D digital images thus captured are then aligned together with appropriate software using
overlapping sections of the images to create an accurate 3D digital model of the object. The
software makes it possible to eliminate redundant points in overlapping sections in order to
generate a homogenous density of 3D points throughout the model. Some scanners capture
the color directly with laser scanning - in this case, RGB values (Red, Green, Blue) are
recorded along with the X, Y, Z coordinates - or indirectly by mapping a color photograph
taken while scanning the 3D digital image. In the latter case, lighting conditions will have an
effect on color quality. Here, the term ’’object’’ refers to small, medium and large objects
(ranging from a few millimeters to a few meters in length and width) as well as buildings and
large sites (ranging from many square meters to a few square kilometers in surface area).
According to the object or site to be scanned, the 3D scanning process is carried out by
moving the object in front of the scanner or by moving the equipment around the object or
inside and around the site [2].
Figure 1: Laser scanner and scanned models [3].
Today, we can find a wide range of 3D scanning systems available on the market. The
following main characteristics differentiate these systems:
- Operating mode
- Capacity to capture a given color
- Accuracy of measurement
- Resolution (planar resolution and depth resolution)
- Need to install or not, control targets in the scene to be digitized
- Portability
- Operation range (distance between the scanner and the surface to be scanned).
While operating methods with a 3D scanner are typically quite similar, we will not use the
same 3D scanning system to digitize a small statue, the interior or exterior of a building, or a
human body. The choice of the right system is dictated by the needs and specifications of the
project itself. Thus, a single system will not be suitable for all types of projects [2].
79
A 3-D laser scan produces a precise record of a physical space or object. Initially, the operator
of the system takes a photo-mosaic image with a camera and then marks the area to be
scanned. The laser scanner then rotates robotically, capturing data at a speed of up to 4,000
points per second. The result is a raw image that is loaded into 3-D visualization and
modeling software, which produce accurate existing condition drawings. An example of a
successful implementation of this technology comes from the historic tower that serves as the
headquarters of the Eastman Kodak Company in Rochester, N.Y. Kodak decided to restore
the building's facade, particularly the terra-cotta tile section on the upper four floors of the 19story tower. The team of specialists charged with exterior repair and restoration decided to
use the 3-D laser scanning technology. The entire exterior scan was completed in less than
two weeks from 32 adjacent rooftop or ground-level positions. Approximately 84,000 square
feet of 3-D facade data was collected and entered [4].
3
DATA PROCESSING - SCAN TO BIM
Building Information Modeling is used as a data repository for the project. BIM improves the
quality of building reconstruction preparation. By using this technology it is possible to
determine quantities in high precisions. Combine different materials and verify functionality
through analysis. For all these processes will need to enter information on the current state.
Laser scan method produces clouds of points in CAD as a result of the measurement. Building
information model is essentially based on the CAD environment. It is therefore possible to
use the laser scan method for survey the old state of building. Laser scanners can be used to
capture dense 3D measurements of a facility's as-built condition. It is important to note that
the results of the measurements will always be a cloud of points. It is therefore necessary to
organize points to functional form which can be used or readable for BIM.
3.1 Data preparation
The actual scanning is the least complicated part of the process— the most challenging is the
smooth export to BIM. Infinite views, from any vantage point, are available from the unified
point cloud. Once the 3D point cloud data is consolidated and exported to a CAD or BIM
platform, traditional A/E deliverables such as 2D plans, elevations, and sections can be
readily extracted. While 3D models depict ideal conditions, 3D scans reflect the buildings as
they actually are: seldom perfectly straight, level or plumb. 3D modeling is simplified using
point cloud data for referencing, but the point cloud itself can serve this purpose, saving many
hours of digital model building [5]. Given a point cloud of a facility, the modeling of a BIM
involves three tasks: modeling the geometry of the components (“What is the shape of this
wall?”), assigning an object category and material properties to a component (“This object is
a brick wall.”), and establishing relationships between components (“Wall1 is connected to
Wall2 at this location.”). These tasks do not necessarily take place sequentially, and
depending on the workflow, they may be interleaved [3]. The goal of the geometric modeling
task is to create simplified representations of building components by fitting geometric
primitives to the point cloud data. Geometric primitives can be individual surfaces or
volumetric shapes. For example, a simple wall can be modeled as a planar patch, or it can be a
rectangular box (cuboid). Surfaces like moldings or decorative carvings may not be well
modeled by a simple geometric primitive. In such cases, different modeling techniques can be
used. For linear structures (e.g., moldings), a cross-section of the object can be modeled by
fitting splines to the data and then sweeping the cross-section along a trajectory to form the
object model [6]. More complex structures (e.g., decorative carvings) may be modeled nonparametrically, using triangle meshes, for example, or they can be modeled from a database of
known object models [7]. Since BIMs are normally defined using solid shapes, surface-based
representations need to be transformed into solid models [3].
80
The modeled components are labeled with an object category. Standard BIM categories
include wall, roof, slab, beam, and column [8]. Additionally, custom object categories can be
created based on individual project needs. Objects may be further augmented with other metadata, such as material properties or links to specifications for custom components [3].
Topological relationships between components, and between components and spaces, are
important in a BIM and must be established. Connectivity relationships indicate which objects
are connected to one another and where they are connected. For example, adjacent walls will
be connected at their boundaries, and walls will be connected to slabs at the bottom.
Additionally, containment relationships are used to encode the locations of components that
are embedded within one another, such as windows and doors embedded within walls [9,10].
3.2 Data to BIM process
BIM data import or points cloud export as a most challenging part of the process is done
manually or ´´automatically´´. Literature [3] describes manual and automatic process:
Manual process
Data transfer is divided to two different methods. The first approach is to fit geometric
primitives to the 3D data directly. Geometric modeling software typically includes tools for
fitting geometric primitives, such as planes, cylinders, spheres, and cones to the data, as well
as special-purpose tools for modeling pipes [11]. These tools are semi-automated and require
significant user input. For example, to model a planar surface, the user selects a few points or
a patch of data, and a plane will be fitted to the selected data. The planar patch may be
extended using a region growing algorithm to the extent that contiguous data lie within a
tolerance distance of the initial surface estimate [3]. In this way, approximate boundaries of
the patch can be identified, but, in practice, these boundaries can be irregular and inaccurate
(Fig. 4a).
Fig. 4. Examples of methods for reconstructing an as-built BIM from laser scanner data [3].
81
More regular boundaries can be obtained by intersecting multiple geometric primitives. For
example, the intersection of three orthogonal planes representing two walls and the floor
forms the corner of a room as well as straight line wall–wall and wall–floor boundaries.
Depending on the software, geometric modeling may operate on point clouds or polygonal
(usually triangular) surface meshes. At present, BIM design software does not have the
capability to convert geometric primitives created with reverse engineering tools into BIM
objects directly. Therefore, it is common practice to re-model the geometry within the BIM
design environment using the reverse engineered model as a guide. The need to transfer
models back and forth between several different software packages gives rise to data
interoperability problems as well [3].
The second geometric modeling approach uses cross-sections and surface extrusion (Fig. 4b).
First, horizontal and vertical cross-sections are extracted from the data, and lines are fit to the
cross-sections to represent walls and slabs in plan views. Then, vertical cross-sections are
extracted to determine the heights of walls, and any doors and windows, with respect to the
floor and ceiling. Finally, walls are modeled by extruding the horizontal cross-section
vertically based on the constraints of the vertical cross-sections. This approach is less
computationally intensive than the surface-fitting approach, but it can lead to errors when the
components do not follow their idealized geometries, for instance, if a wall is not truly
vertical [3].
Automatic process
Ideally, a system could be developed that would take a point cloud of a facility as input and
produce a fully annotated as-built BIM of the facility as output. This is a challenging problem
for several reasons. Facilities can be complex environments, often with numerous unrelated
objects, such as furniture and wall-hangings, which obscure the view of the components to be
modelled. Depending on the information requirements of project participants as well as the
context of a project, the problem of as-built BIM reconstruction can have several variants in
terms of available inputs and expected outputs. On the input side, additional information
about a facility, beyond the raw point cloud data, may be available. This information may be a
previously created as-built or as-designed model. We can distinguish between variants by the
dimensionality (2D plans and elevations or full 3D CAD models) and the level of semantics in
the a priori data (e.g., geometry, object labels, object relationships). Such prior information
can simplify the BIM reconstruction process because the prior model can be aligned with the
collected data, and knowledge gleaned from that prior model can serve as guidance [3].
4
CONCLUSION
Building renovation and reconstruction increases. Therefore it is very important to deal with
the implementation of advanced technology in this field. Adaptation Laser Scanning seems to
be a wery powerfull tool to support BIM. The problem remains the automation of data
collecting process. Progress could bring allocation information on admission. Cloud of points
could recognize materials by resolution, reflectivity, structure or temperature. This area
requires a more profound discussion. In any case, this technology will bring the quality of the
process, speed and accuracy.
Acknowledgment
Article is the result of the Project implementation: University Science Park TECHNICOM
for Innovation Applications Supported by Knowledge Technology, ITMS: 26220220182,
supported by the Research & Development Operational Programme funded by the ERDF
We support research activities in Slovakia
82
The authors are grateful to the Slovak Grant Agency for Science (Grant No. 1/0840/11 Multidimensional approaches supporting integrated design and management of construction
projects) for financial support of this work.
References
1.
GEOFF J. High-Definition Surveying: 3d Laser Scanning, Professional Surveyor
Magazine, 2005 http://www.iafsm.org/Resources/Documents/pms/16.pdf
2.
http://www.mcg3d.com/article.php3?id_article=33
3.
TANG P., at all, Automatic reconstruction of as-built building information models
from laser-scanned point clouds: A review of related techniques, Automation in
Construction, 2010 pp 829–843
4.
MERRITT B., 3-D Laser Scanning Speeds Up Building Condition Surveys, Design
& Construction,2009 http://www.facilitiesnet.com/designconstruction/article/3DLaser-Scanning-Speeds-Up-Building-Condition-Surveys--11353
5.
PAGE S. 3D Laser Scanning: As-Built Reality Capture for BIM, AECbytes
Viewpoint #66 ,2012, http://www.aecbytes.com/viewpoint/2012/issue_66.html
6.
DELUCA L., at all, Reverse engineering of architectural buildings based on a hybrid
modeling approach, Computers & Graphics, 30 (2), 2006, pp. 160–176
7.
CAMPBELL R., FLYNN P, A survey of free-form object representation and
recognition techniques, Computer Vision and Image Understanding, 2001, (CVIU),
81 (2)), pp. 166–210
8.
REVIT ARCHITECTURE - Autodesk, Inc., - http://usa.autodesk.com/adsk/servl
et/index?id=3781831&siteID=123112.
9.
BINFORD T.O. Visual perception by computer, Proceedings of the IEEE
Conference on Systems and Control, Miami, FL, 1971
10. INDUSTRY FOUNDATION CLASSES (IFC) - BuildingSmart, International
Alliance for Interoperability - http://www.iai-tech.org/.
11. POLYWORKS - Innovmetric Software, Inc. - www.innovmetric.com.
Contact
Ing. Tibor Šoltés
Technical University of Košice, Faculty of Civil Engineering, Institute of Construction
Technology and Management, Slovakia
[email protected]
Prof. Ing. Maria Kozlovská, Ph.D.
Technical University of Košice, Faculty of Civil Engineering, Institute of Construction
Technology and Management, Slovakia
[email protected]
83
UTILIZATION OF CONSTRUCTION WASTE IN THE
IMPLEMENTATION OF BUILDINGS
Lukáš Prokopčák, Katarína Prokopčáková
Abstract
Researches show that in the branches of industry in the EU is construction the third largest
polluter of the environment and building waste accounts for about one third of the total
volume of generated waste. Requirements for ensuring protection of the environment are
more challenging for the qualitative properties of building materials, technological processes
of construction, construction machinery and etc. Therefore are in the construction industry
and building production the necessary constantly trying to eliminate environmental impacts of
the construction. One option how to reduce the burden on the environment is to introduce
new, progressive construction technologies and methods - modern methods of construction
(MMC), which allow the reduction of construction waste and not least priority becomes the
use of construction waste, so that it can be „re“ used.
Key words: construction waste, protection of environment, reducing the amount of waste
INTRODUCTION
Environment is becoming a significant development potential of a country and the effort
dwells in minimizing the negative impacts affecting its quality. Requirements of securing the
environmental protection are more demanding when it comes to qualitative properties of
construction materials, building machines, technological building processes, etc. Due to this it
is necessary to come from the confrontation of the current status with requirements of
securing maximum effectiveness of the building production process at minimizing negative
impacts on the environment.
1. CONSTRUCTION WASTE AND ITS GENERATION
There is no exact definition of the notion of construction waste in Slovakia. Act 223/2001
Coll. valid in the area of Slovakia only defines the notion of waste. According to Slovak
legislature, construction and demolition waste represent the waste generated as a result of
building activities, securing activities, as well as activities performed during maintenance
work, reconstruction or demolition.
1.2 Waste generation in Slovakia in the years 2005 – 2012.
Over 10 million tons of waste per year was generated during the evaluated period (except the
year 2009) in Slovakia. Exceptional amount of waste was noticed in year 2006 which was
caused by one-time throwing out of the excavated soil generated during building of motorway
feeders and Sitina tunnel in Bratislava, as well as throwing out of ruins in U.S. Steel Košice.
Decrease of the generated waste in the year 2009 is a consequence of the economic crisis,
which resulted mainly in an attenuation of industrial activities, what was subsequently
reflected in the decrease of the generated waste.
Judging from the above mentioned information, the level of the waste valuation in Slovakia in
that period did not reach even 60% and the level of energetic valuation it fluctuated from
1.8% (in the year 2006) to 5.1% (in the year 2008). As it is clear from this information,
dumping of the waste prevails over other forms of handling. In the evaluated period 37,7% (in
the year 2005) to 50.9% (in the year 2007) was dumped. Some small amount of waste (0.57%
- 2.60%) was burnt without any energetic utilization.
84
2. PROCESSING AND UTILIZATION OF THE CONSTRUCTION
WASTE
Construction waste is considered to be one of the main factors affecting the environment. This
is why in the building industry it is necessary to constantly eliminate environmental impacts
of the construction itself. One of the options how to decrease the environmental encumbrance
by waste is reusing of the construction and demolition waste. Mainly waste representing a
source of saving of primary raw materials is generated. Exhaustible raw material sources are
saved through an effective utilization of the construction waste and new values are produced.
2. 1 Waste dumps
Dumping is the oldest, the most simple and the most wide-spread method of waste disposal.
More than 90% of solid waste is dumped even in the developed countries. Abandoned
quarries, sand mines, swampy ground, unmanaged free places without special modification
have been used for dumping of the waste in the past and often even nowadays – we speak
about unorganized dumping.
These unorganized dumping places endanger the environment, they often represent a source
of a chemical and biological contamination of surface and ground waters, they aggravate the
environmental hygiene (smell, smoke, appearance, spreading of infectious diseases) in large
surroundings and endanger health of people. In the present practice it is common that only
after the capacity of the dumping place was reached, it was so-called re-cultivated, which
means that they were covered by soil. This way of ending of a dumping place was often a
reason why the negative influence of the dumping place on the environment of the
surrounding area was not eliminated, but it continues.
The fundamental prerequisite for safe dumping of the waste is organized dumping. It is
arranging of solid waste in layers using such technology, which reduces jeopardy of the
regime of underground waters and maintains hygienic and aesthetic conditions of the given
area, while the resultant product is a re-cultivated dumping place.
2.2 Waste recycling
Recycling could be most broadly defined as repeated utilization of any material. According to
a generally accepted definition recycling represents extensive repeated returning of solid,
liquid and gaseous waste products back into recirculation and repeated utilization of waste
energy and heat. The focus of recycling is remains, i.e. what is left from the production or
consumption of products. From those remains, which are not recycled, is generated waste,
which gets into the natural environment. Even end products, objects of a long-term
consumption after the social utilization, when not recycled, become waste. Recycling thus
represents processes which bring the generated waste back into the production where it serves
as a raw material when getting new products or as a source of energy. It is mostly possible to
come across the recycled material in the road and building construction. From the point of
view of quality it is possible to divide individual ways of utilization into quality (concrete,
roads, etc.) and inferior (field-engineering, backfilling, foundations, etc.)
The following conditions apply to all the utilization of the recycled material:
• The material has to meet requirements of not being health-endangering. The maximum
accepted volume of harmful substances (oils, polychlorinated biphenyls, aromates,
heavy metals, salts, radioactivity) is exactly set by standards. The reason is danger of
contamination of underground waters by the above mentioned harmful substances
when used in building and road construction. This explains the endeavour to get the
most homogeneous material. It is very important to pre-sort inappropriate material
(wood, PVC, iron, polystyrene, etc.) which has to be removed.
85
•
•
The material has to meet regulations of individual standards depending on its usage, so
that the resultant product has approximately the same characteristics in comparison
with the natural material.
Utilization of the recycled material has to be economic. With conditions representing
the appropriate environment to place the recycling line, it is necessary to include
dumping fees, transport fees, material processing fees and prices at which the
secondary raw material could be sold. Effectiveness of the processing of the building
and demolition waste is a result of combining these items, which are variables.
2.3 Construction waste as renewable material
From the ecological point of view the construction waste is mostly not harmful to its
environment because it mostly does not contain any harmful or toxic substances, but due to its
great volume it becomes unbearable for the dumping places. Only in the 80´s an increased
pressure on the processing and repeated utilization of the waste material can be observed
which was influenced by ecological measures, lack of storage places and an increased price of
the natural stone. These ecological problems have been minimized in the industry of the
developed countries by processing of the construction waste with the aim of utilizing this
material as a raw material in the building industry and building production.
Assessing of the waste and minimizing of its negative influence on the environment belongs
among strategic tasks of the environmental policy of Slovakia. The area of construction and
industry of construction material offers a great possibility of valuation of the waste of various
types. For the energetic waste, storing of which is a great burden for the environment, there is
an endeavour to create better conditions for further utilization as it has been for far.
The purpose of waste handling has been defined, as follows:
• to prevent and limit the production of waste,
• to valuate the waste through recycling, repeated utilization or other processes enabling
obtaining of the secondary raw material,
• to utilize waste as a source of energy,
• to dispose the waste.
If we want to deal with possibilities of utilization of the generated waste, it is
necessary to know its types, physical and chemical characteristics and based on this to create
ways of its separation and further usage. At the same time it is necessary to evaluate
possibilities of its utilization in the process when it is generated, utilization for other building
processes or for other economic sectors. Table 1 shows an example of utilization of the
building waste – concrete, brick and its repeated utilization in the building production. Table
2 introduces selection of utilization of the building waste.
Table 1. Possibilities of utilization of concrete and brick waste material
Ser. Nr.
1.
2.
3.
4.
5.
Material
Waste
Ground, crushed concrete
Concrete roads, bridges, airports, pipes
Ground concrete, brick
Buildings (foundations, floors, walls, etc.)
walling
Ground concrete, brick
Cable feeding
walling
Basic playground material for playgrounds, Ground concrete, asphalt
yards
blend
Pavements, touristic paths, temporary roads
Ground concrete
Ground concrete, bricks,
Roads, car parks, lay-by parking
asphalt blend
Utilization
Secondary raw material
for concrete
Packing material
Secondary raw material
for asphalt blends
Substitution of gravel
Foundation layers
86
Table 2. Utilization of construction waste and possibilities of its utilization – selection
Code
Name
Suitable
recycling
technology
Suitable
mechanisms
Possibilities of
utilization
Possibilities
of valuation
in %
Component for
new concrete,
component for
new asphalt
100%
Note
Concrete roads, bridges,
airports, pipes, basic
playground material for
pavements and yards
Buildings (foundations,
floors, horizontal
separating constructions,
walls), trench of cables,
pavements (cycling,
pedestrian), forest and
field paths, temporary
roads on a building site
17 01
01
Concrete
Grinding
Grinding
lines
17 01
02
Bricks
Grinding
Grinding
lines
Packing material,
substitution of
gravel
100%
Grinding
Grinding
lines
Packing material,
substitution of
gravel
100%
Trench of cables,
pavements, temporary
roads on a building site
Grinding
Grinding
lines
Substitution of
gravel
100%
Trenches, pavements,
roads, car parks, lay-by
parking
Splitting
and
grinding
Machines for
grinding
wood mass
Ground material,
cleft for
production of
building material
80%
Indoor usage
100%
Possibilities of
utilization
Possibilities
of valuation
in %
Note
Indoor usage
95%
Decorative material,
separating walls, interior
accessories
Mill
Cables in building
industry
100%
Production of cables,
wires and tubes
Mill
Constructions
where high
corrosion
resistance is
required,
moderately
stressed segments
100%
Face-brick profile, profiles
for production of doors
and windows, facade
panels
Melting
furnace
Repeating usage
80%
Construction material,
steep profiles and consoles
17 01
03
17 01
07
Linings,
floor tiles
and
ceramics
Blends of
concrete,
bricks,
linings,
floor tiles,
ceramics
other than
170106
17 02
01
Wood
17 02
02
Glass
Code
Name
17 02
03
Plastics
17 04
01
Copper,
bronze,
brass
17 04
02
17 04
05
Recycling done at
specialised facilities
Suitable
recycling
technology
Recycling done at
specialised facilities
Grinding
Aluminium Grinding
Iron and
steel
Suitable
mechanisms
Melting
Horizontal constructions,
casing, timbers of roofs,
staircases, floors,
supporting material
Decorative material, glass
adapting pipes, reglazing
of opening fillings of
external cladding
87
17 05
04
17 05
06
Soil, gravel
and other
than
mentioned
in 170503
Excavated
soil other
than
mentioned
in 170505
Sifting
Sieve
Floor base
100%
Levelling of excavations
and banks during ground
works
Sifting
Sieve
Floor base
100%
Levelling of excavations
and banks during ground
works
CONCLUSION
In this time of the sustainable approaches has the priority position the problem solving of the
huge amount of construction waste and its use. By effective use of the construction waste we
are trying to conserve exhaustible mineral resources and produce a new value. State by the
legislative steps has already supported the dynamic progress in this direction, but they have
not been applied in the greater extent in building practice. Improvement can occur only by
editing the appropriate existing technologies and especially by the using of appropriate
methodology for waste treatment and his "put back" into the building production.
The presented paper offers an analysis of the problem of generation and processing, in some
cases even utilization of the construction waste. Department of building technology STU in
Bratislava deals with the problem of the waste handling with an emphasis placed on the
solving of the optimalization methods of the construction waste processing assuming building
effectivity, minimalization of impacts on population and environment – project VEGA Nr.
1/0184/12.
The negative influence on the environment has been so significant over the past quartercentury and the ecological balance is being damaged to such an extent, that the nature will not
be able to provide basic conditions for healthy development of a human on the Earth without
any scientific regulation. These human interventions in the environment are no longer of a
local and regional character, but of a global effect. The building production unquestionably
belongs among the factors negatively influencing the environment and our task is to solve
these problems in all countries of the world.
Sources
1.
Zákon NR SR č. 409/2006 Zb. z. o odpadoch a o zmene a doplnení niektorých
zákonov v znení neskorších predpisov .
2.
Program odpadového hospodárstva na roky 2011 – 2015.
3.
Vyhláška MŽP SR č. 284/2001 Z. z., ktorou sa ustanovuje Katalóg odpadov v znení
neskorších predpisov .
4.
LAURITZEN, K.,: Recycling concrete - an overview of development and challenges
[online]. In: 2nd International symposium on Nanotechnology in construction, 2005.
Dostupné na internete: http://www.mmsconferencing.com/nanoc/pdf/034ID193.pdf
5.
SVOBODA, K: Využití stavebních a demoličních odpadů, Závěrečná zpráva projektu
VaV 720/2/03, Praha 2004.
6.
HYBEN, I., CAIS, Ľ.: Recyklácia stavebných odpadov – hlukové charakteristiky
recyklačných strojov. In: Recycling 2004, Brno, 2004, str. 84 – 89.
7.
NEVICKÝ, H. a kol.: Príprava, vedenie a organizácia stavieb. In: Verlag Dashöffer,
(NSR) ISSN: 1335-8626, Bratislava, 2003, str. 1 - 12
88
Contact
Ing. Lukáš Prokopčák
Stavebná fakulta STU - Katedra technológie stavieb,
Radlinského 11, 813 68 Bratislava,
e-mail: [email protected]
Ing.Katarína Prokopčáková, PhD.,
Stavebná fakulta STU - Katedra technológie stavieb,
Radlinského 11, 813 68 Bratislava,
89
TYPOLOGY OF KNOWLEDGE TRANSFER FROM FACILITY
MANAGEMENT TO CONSTRUCTION PROJECTS
Peter Podmanický, Ivan Hyben
Abstract
Typology of knowledge transfer from facility management to construction projects are to
some extent always partial address, but so far lacked knowledge transfer facility management
framework that would further describe the mechanism, thus the issue more transparent.
Therefore, the article focuses on the understanding of development issues and the application
of knowledge management facility, already at the stage of project preparation of new objects.
Key words: facility management, knowledge transfer, construction projects
1
INTRODUCTION
Development of building projects are characterized by increasing complexity due to many
new requirements, technologies and materials, as well an increasing number of different
parties involved in the project. The introduction of FM to construction projects increases their
complexity, but it is known that the connection information is a major problem in the design
(Kreiner, 2005). It is possible to argue that if we increase awareness of FM, will be at the
expense of other areas that may be equally important. However, proponents of applying FM
to design the final building inspection of buildings, argue systematic process that ultimately
will help simplify the process and comprehensively understand the complexity of the project
(A'gu'stsson, 2010).
When we look at knowledge transfer from FM to design new buildings, so we can see clear
differences between facility managers who will support the operation of objects and those
who focus on business support and on the other hand, the professionals who are from
construction companies and focus on delivering projects for new buildings. Johnstone (2007)
described the differences between professionals who are dedicated to report objects and
designers, for example, farmers and hunters, based on a study from the United Kingdom
(UK). Facility managers as farmers focus on developing long-term relationships, but
professionals in the field of design are like hunters focus to capture new contract and rapid
completion of the project to be able to pounce on the next "victim".
2
SUMMARY OF PREVIOUS ADDRESSING
The first draft typology of knowledge transfer from FM to design the new building
constructions based on the study of literature and case studies ( Jensen , 2009a). This article
has been further developed typology to a greater extent , focused on knowledge transfer from
FM to design. The typology was developed based on literature that deals with theories FM,
Knowledge Management ( Knowledge Management - KM ) and project management. The
typology is divided into two parts, both of which are based on mechanisms of knowledge
transmitted proactive and reactive. The first part focuses on knowledge transfer requirements
and the building structure, knowledge transferred from FM to draft with documents. The
continuous input instruction is central to this section. The second part focuses mainly on
efficiency and operational performance of buildings. Final inspection is the central point of
this section. The typology consists of four mechanisms of initial knowledge transfer
mechanisms and four reverse knowledge transfer .
90
Barriers to knowledge transfer in the field of FM in the design of new buildings have been
investigated in ongoing research projects in Denmark. The results show a number of different
obstacles, which are grouped into groups. They are the ones associated with the project itself,
further structural and legal barriers, barriers related to competencies and sociological barriers.
It also shows the possible solutions, both short and long term. The case study, which is part of
the same research, it should be noted that a number of issues concerning the FM tasks are
designed as an interdisciplinary nature. Nevertheless, it is possible to solve these problems in
a systematic manner ( Hansen , Damgaard and de Haas , 2010).
Similarly, research is under way in the area of knowledge transfer between FM and design
phase in relation to industrial systems . Vianello & Ahmed , 2009 , 2009b create a framework
where different forms of knowledge are located in the so-called . data , information and
knowledge of the hierarchy , as a pyramid , where the data is located at the bottom and at the
top of the knowledge . Knowledge transfer process is characterized in that the individual
knowledge entered either in the form of data , or transmitted in the form of knowledge.
Transfer mechanisms are defined as forms of transmission , which includes fixed strategy of
personalization and codification . The transfer of knowledge from the FM into buildings takes
place primarily in the design phase . Cooperation with facility management team of designers
is an exception and occurs when critical issues are addressed , which require expression of
facility management . Problematic is the transfer of knowledge from the later stages of the life
cycle of buildings , which tends to be very dynamic.
3
TYPOLOGY OF KNOWLEDGE TRANSFER FROM FACILITY
MANAGEMENT TO CONSTRUCTION PROJECTS
The typology is developed in several steps. The first part involves what is called proactive
knowledge transfer from FM to building structures. This section was originally developed in
2008 based on the study of literature combined with 36 case studies from Denmark, Norway,
Sweden, Finland and Iceland as well as other, as referred to in Article (Jensen, 2009). The
first version contained the following four mechanisms of transmission:
• Codification of knowledge of the operation of buildings, which can increase awareness
of designers.
• Dealing with the competencies facility managers who can work with designers.
• Ensuring that designs and solutions to facility managers are taken very seriously and
their application in the design through the settlement of the question of competence.
• Ensure that the codified knowledge of the operation of the buildings were used in the
design.
The concept of continuous briefing and continuous improvement are fundamental aspects of
the typology. The idea to combine these concepts are born in early 2009. The result is an
imaginary symmetry between knowledge transfer from FM to construction projects and
efficient operation. Subsequently, the methodology developed and presented in the article
(Jensen, Damgaard, and Kirstiansen, 2009).The transfer of knowledge from the field of FM in
the design of new buildings is seen as a combination of knowledge applied forward and
backward (Le, 2007, Vianello & Ahmed, 2009a, 2009b).
91
Figure 1 Typology for front- and back-end knowledge transfer from FM to the building
projects (Jensen, 2012)
Figure 2 The pincer movement of FM to the building projects (Jensen, 2012)
At the beginning of the design processes and building knowledge particularly in relation to
organizations that will use it. Define the requirements in relation to design object itself,
therefore typology in this section deals primarily with the proposal itself. While the retransmission of knowledge is mainly engaged in the actual performance of the building, effect
of technology, functionality and usability, especially in relation to the rapidly changing needs
of society during the use of the property.
3.1 Mechanism of proactive knowledge transfer
In this case, at the forefront of the sender of the query that includes the client, can be
represented by facility managers, users and consultants in various fields. In the form
recipient's design team of designers. The requirement to transfer knowledge from FM can be
divided either between competent parties to the design process, or may be divided by
codification. This distinction is based on the differentiation between strategy, personalization
and codification (Le, 2007, Vianello & Ahmed, 2009a, 2009b). The term "qualified
participants" is used because, research and experience show that different parties, without the
responsibilities exacerbated the process. Largely depends on communication between teams
of designers and investors.
92
3.2 Mechanism of reactive knowledge transfer
In this case, the methodology involves the user in the form of specialists in the operation of
facilities, and facility managers who specialize in the operation of facilities, companies that
provide services in the field of FM and consultants. The requirement to transfer knowledge
from FM can be shared between the integrated FM and outsourcing. The distribution is based
on how the question of how society is taking, or rely on its own staff or FM area provides
outsourced. Requirement reactive transfer of knowledge can be shared between enlarged
responsibility and enhanced form of control. Form distribution is based on the differentiation
between management relations within the organization and the relationship represented by
(Milgrom and Roberts, 1992).
4
CONCLUSION
The difference between the operator by transferring ahead and recoveries in FM can be
likened to the difference between the requirements of the new building and performance alone
objects that are already standing. The difference is much more relevant in the construction
industry than in other industries. An example might be the energy consumption of objects,
which in the design of new buildings often dealt with outside consultants to the extent that it
is consistent with customer requirements and regulations. However, the actual cost of the
operation is often inconsistent and does not assume responsibility nobody. In this issue we
could in the future be avoided. Typology introduces the concept of knowledge transfer from
the FM to construction projects. It is seen cutting the proactive and reactive activities. In both
cases, it is particularly important collaboration, communication and codification of
knowledge, and to allow their use in the design of new buildings.
Sources
1.
A´GU´STSSON, R.O¨. (2010). Building commissioning – Advantages and
disadvantages of the process and how it has been applied in Denmark (Master
Thesis, Department of Management Engineering, Technical University of Denmark).
2.
HANSEN, A.P., DAMGAARD, T., & DE HAAS, H. (2010, May). Creating and
using FM knowledge in complex building projects. Constructions Matter
Conference, Copenhagen Business School, Copenhagen.
3.
JENSEN, P.A., DAMGAARD, T., & KRISTIANSEN, K. (2009, October). The role
of facilities management in building projects. Proceedings of Changing Role ’09
Conference, Nordwijk aan Zee, The Netherlands.
4.
JOHNSTONE, S. (2007, May). Hunters and farmers? The HRM implications of
product-service in construction. Proceedings from CIB World Congress in Cape
Town. Rotterdam: CIB.
5.
JENSEN, P.A. (2009a). Design integration of facilities management: A challenge of
knowledge transfer. Architectural Engineering and Design Management, 5, 124–135.
6.
KREINER, K. (2005). Knowledge management challenges in the construction sector.
Copenhagen: Copenhagen Business School.
7.
LEˆ, M.A.T. (2007). Linking experience and learning: Application to multi-project
building environments. Engineering, Construction and Architectural Management,
14(2), 150–163.
8.
MILGROM, P., & ROBERTS, J. (1992). Economics, organization & management.
New Jersey: Prentice Hall.
93
9.
10.
11.
PER ANKER JENSEN (2012). Knowledge transfer from facilities management to
building projects: A typology of transfer mechanisms. Department of Management
Engineering, Technical University of Denmark, Centre for Facilities Management –
Realdania Research, Denmark.
VIANELLO, G., & AHMED, S. (2009a, August). Knowledge transfer between
service and design phases in the oil industry. International Journal on Engineering
Design ICED’09, Stanford University, California, USA.
VIANELLO, G., & AHMED, S. (2009b, August–September). Investigating
knowledge transfer mechanisms for oil rigs. Proceedings of the ASME 2009
International Design Engineering Technical Conference & Computers and
Information in Engineering Conference, IDETC/CIE 2009, San Diego, CA, USA.
Contribution represents partial output of the project VEGA 1/0840/11 "Multi-dimensional
approaches supporting integrated design and management of construction projects."
Contact
Ing. Peter Podmanický
Ústav technológie a manažmentu v stavebníctve
Tel: 055-602 4385
prof. Ing. Ivan Hyben, PhD.
Ústav technológie a manažmentu v stavebníctve
Tel: 055- 602 4377
94
INQUIRY INTO CRITICAL RISK FACTORS IN CONSTRUCTION
PROJECTS
Zuzana Struková, Mária Kozlovská
Abstract
Due to the nature of the construction projects consisting of many related and none-related
operations, many risk factors contribute in a project. The practical application of Project Risk
Management is a key element in the success of any project, it should form part of the project
management routine at all stages of the project life-cycle. Parties engaged in construction
project (owners, designers, contractors) should understand the risks involved in construction
project in order to reduce them to good effect. However, regarding their low awareness in
ways to prevent and manage the risks, they usually underestimate the value of effective risks
management. The paper mentions the level of awareness in construction process risks
understanding and managing and presents the results of studies intent on critical construction
projects risks and risk factors determination, classification and their significances scaling.
Key words: risk, risk factor, construction project, risk management, construction aspect
1
INTRODUCTION
The construction sector, involving diverse stakeholders, long production duration and a
production system inducing significant interaction between internal and external
environments, is considered as a risky business. The complexity and the strategic nature of
products are typical for the industry. Construction projects are well known for their unique
and uncertain characteristics. No construction project is risk free. At any stage of a life cycle,
a project is troubled with various risks. Risk is manageable, diminishable, transferable or
acceptable; it cannot be ignored (Latham, 1994).
Risks are harmful to construction projects themselves by causing failure or loss, but it should
be noted that contractors also suffer from those risks, particularly uncertainties that have
dramatic impacts on their own benefits, making them evaluate the situation and potential risks
thoroughly before making decisions. Underestimating of risk management in construction
projects may affect adversely the profit of company involved in a project as the contractor. It
is not rare that risk slight results in company decay. Unfortunately, the construction industry
world over has a poor reputation in risk analysis when compared with other industries such as
finance or insurance (Laryea and Hughes, 2008). The adoption of the available tools and
decision support systems is quite limited. There is a heavy reliance on practical experience
and professional judgement when assessing construction risk.
2
RISK MANAGEMENT IN BUILDING INDUSTRY: CURRENT
CONDITIONS
In order to manage a construction project, Risk Management must be used as one of the
essential parts in project management. Nowadays, risk management in construction is
acknowledged as a very important part of project management and a very important part of
project management and a very interesting subject to write about as well. It is frequently
discussed, but the practice is still at an inadequate level (Burcar Dunovic et al., 2007).
95
Reasons vary from the lack of knowledge to implementation of risk management or the lack
of resources. Generally, the reasons are mostly related to a poor knowledge of risks per se.
Wang and Yuan (2011) adopted several statistical analysis techniques, including ranking
analysis and factor analysis, to identify the critical factors affecting contractors` risk attitudes
in construction projects. The identified critical factors (according to the ranking results)
imply: i) consequences of decision making, ii) engineering experience, iii) completeness of
project information, iv) sensitivity to external information, v) decision motivation, vi)
professional knowledge, vii) education background, viii) scope of knowledge, ix) boldness, x)
judgment ability, xi) company`s economic strength, xii) social experience, xiii) values, xiv)
interest in the engineering, xv) desire for decision objectives, and xvi) external economic
environment. Among the 16 important factors, only 4 are regarding the external environment,
while other 12 factors highly depend on contractors` experience and personal characteristics.
In order to recognize the current conditions of research centred on construction risk
management in Slovak Republic, we have reviewed of the published literature of construction
project risk management in the country. We found that there is the absence of a complex
literature on risk in construction projects. The conference and journal papers and some book
publications dealing with approaches to specific risks management (safety, environmental,
financial, ...) are sporadic. In Czech Republic, there is only little better situation. In the
methodical set of recommended standards, developed and published in 2000 by the Czech
Chamber of Authorized Engineers and Technicians in construction (Kupilík et al., 2000), is
stated that the research on risk management in Czech Republic is neither developed or is
insufficient. However, this publication provides a holistic analysis of construction risk
modelling and it is considered to be the turning point of trend in research related to
construction risk in Czech Republic. The all parties involved in construction projects are
asked to deal intensely and systematically with risk assessment, modelling and management.
The coming globalization brings some changes to project management in construction.
Primarily, the “new” risks (till then substandard or just ad-hoc managed) start to range in
construction projects. Next, the globalization involves different pressures on ready
identification and rational management of risks in projects. However, in construction industry
in Slovakia, the term risk is still understood too much “generally”. The risk is understood to
be just an event causing some material or other loss, nothing more. The risk management is
not well-practised in the sector due to the lack on risk management knowledge. It is important
to understand risk management knowledge amongst the construction practitioners in order for
them to practise the risk management in handling their projects. The risk awareness in
advanced countries is much better. In these countries, the Risk Management presents an
inseparable part of project management. The lasting market environment in advanced
countries is due to the fact that risk management presents the natural integral of each activity
related to construction in these countries. There is the big amount of published contributions,
as conference papers, journal papers, case studies, books ... and specific internet portals
involving different approaches and studies relating to risk assessment and modelling (e.g.
Construction Risk Management Library, WBDG Risk Management, IRMI - Construction
Risk Management ...). The process of risk management in project management has been
widely studied in organizations and institutes across the world. For example, the Project
Management Institute, the International Organization for Standardization and the Institute of
Risk Management have published their standards on risk management process.
Abroad, researchers have investigated many different theories, tools and techniques for aiding
risk management in building industry. Even if, Taroun (2013) in his insights from a literature
review stated that there is still a plain gap between the theory and practice of risk modelling
96
and assessment. In order to review the historical development of risk modelling and
assessment, he conducted the search targeted all of the available articles in the databases.
According to him, it is of crucial importance to understand the actual practice of risk analysis
and review the development of construction risk modelling and assessment in an attempt to
research viable alternatives that may contribute to closing this gap. The review made by
Taroun demonstrated a remarkable contribution of the researchers towards advancing risk
modelling and assessment. The existing body of knowledge demonstrates a sound basis from
which to investigate novel alternatives that can bridge the existing gap between theory and
practice. Moreover, he found that there was an evident shift from perceiving risk as an
estimation variance towards considering it as a project attribute. Unless, his review has
confirmed that the literature lacks a comprehensive risk assessment framework which
considers the different types of impact of a risk on different project objectives simultaneously.
3
KEY ASPECTS OF CONSTRUCTION PROJECT MANAGEMENT
Construction Project Management is the application of knowledge, skills and techniques to
project activities in order to achieve the objectives of the project. A direct relationship
between effective risk management and project success is acknowledged since risks are
assessed by their potential impact on the project objectives.
In Technical University of Košice (Faculty of Civil Engineering, Institute of Construction
Technology and management), we have been dealing with analysis of risks in construction
projects, especially with those resulting from construction time reducing. Within the research,
the key aspects of construction project management have been studied. The examination is
based on multiple methodical levels, dealing with construction processes issues. On the basis
of the model, respecting the intersection of different methodical levels of:
• project objectives management,
• construction process arrangements,
• technological instructions,
• processes relating to project management (under ISO 10006 standard),
• integrated management system,
the key aspects of construction projects were found. The aspects were determined upon
frequency of an aspect in specific methodical level (Tab. 1). From the research study is
evident that within the frame of common methodical approaches applied in construction
project management, the aspect of risk figures rarely, even though risk aspect threaten each of
other aspects.
Tab.1: The construction aspects prevalence in the context of methodical levels of construction
process examination
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Aspect
frequency
Integrated
management
system
x
x
x
x
Technological
instructions
Project
management
processes
Cost
Time
Quality
Resources
Workers
Technologies
Construction
process
arrangements
Aspects of construction
project management
Project
objectives
management
Methodical levels
4
4
4
4
4
3
97
Work environment
Environmental protection
Occupational safety
Coordination
Communication
Risks
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
3
3
3
2
2
2
Each project, as a unique complex of activities aimed at the objectives achievement, ranges
some risks which should be identified and managed. In regard to the implication, we can
hypothesize that all aspects of a project implies some risk potential. In order to risks
reducing, all the aspects should be managed by the well-functioning system and by skilled
persons with high understanding and awareness of the aspects.
However, the construction parameters which are contractually agreed are indeed critical for
construction projects management. It is concerned: contract sum, construction time, subjectmatter of a contract and quality (parameters specification). While in terms of threats to treaty
commitments, a number of risks can arise for contractor.
The contract sum may be broken on account of: wrong estimated construction cost,
inaccurately assigned resources requirements, change of technology-organizational variants
(methods) , estimated cost overrun, penalties, price changes, ... etc. The construction time
may extend because of: subcontractors delay, climatic conditions, inaccurately estimated time
of construction works performance, material and products supplies delay, incomplete project
documentation, archaeological finds ... etc. The subject-matter of a contract may be
influenced negatively by: incomplete project assignment, incomplete building documentation
and frequent changes during project execution. The construction quality may decrease
because of: technological instructions violation, insufficient competence of workers,
insufficient quality of construction material and products, ... etc.
Moreover, occupational health and safety and environmental protection also belong to critical
aspects of construction process. Generally, these aspects are not definite from contractually
agreed parameters point of view, but they are obligatory in terms of law. They surely include
a number of risks, similarly as before mentioned key aspects. Other aspects of construction,
presented in Tab. 1: resources, workers, technologies, and work environment belong to
aspects which influence markedly the aspects listed above (price, time, amount of work,
quality, occupational safety, environmental protection) and similarly involve various risks in a
broad. Rest of the construction aspects - coordination and communication – may be
characterized as so called management-administrative environment of construction
management. Naturally, they also imply some risks.
In another research study, centred on the added value of development projects in Slovakia, we
found the construction aspects the most important according to Slovak developers.
Following the results of the study, the most crucial aspects of development projects
preparation and execution include: management of interdependencies, quality, strategy and
cost (Fig. 1). Almost the same frequency of the aspects in the survey results is noticeable.
The communication and time aspects are slightly less rated as the most important construction
aspects. Low frequency of risks in the aspects indicated as crucial construction aspects shows
evidence of risks issues underestimating by developers in Slovakia. Moreover, the result of
occupational safety aspects and environmental aspects as well as aspects related to human
resources mention underestimating of important factors of projects management.
98
Fig. 1: Importance of factors influencing development projects
4
CRITICAL RISKS AND RISK FACTORS IN CONSTRUCTION
PROJECTS
There are many different risk sources in the construction projects and some approaches have
been suggested in the literature for classifying them. The source of risk includes inherent
uncertainties and issues relative to company`s fluctuating profit margin, competitive bidding
process, weather change, job-site productivity, the political situations, inflation, contractual
rights, and market competition, etc. Generally, risk factors in a project can be categorized
based on their source and effect on project objectives and can be categorized in external,
internal and legal categories. Sources of risk have been investigated in many past studies
conducted by foreign researchers. Frequent identified categories of risk factors/dimensions
for construction projects are listed in Tab 2.
Tab. 2: List of risk factors/dimensions for construction projects
Risk dimensions
Ten dimensions: Owners, Designers, Contractors, Sub-contractors,
Suppliers, Political, Social and Cultural, Economic, Natural, Others
Five dimensions: Contractor capability related, Contractual and legal
related, Economic related, Physical related, Political and societal related
Eight dimensions: Technical risk, Managerial risk, Resource risk,
Productivity risk, Design risk, Payment risk, Client risk, Subcontractor risk
Five dimensions: Cost related risks, Time related risks, Quality related
risks, Environment related risks, Safety related risks
Five dimensions: Estimator related, Design related, Level of competition
related, Fraudulent practices related, Construction and economic related
Author(s)
El-Sayegh, 2008
Lam et al., 2007
Dikmen et al., 2007
Zou et al., 2007
Baloi and Price, 2003
The most effective critical risk factors which have a significant effect on construction projects
scope can be mostly categorized in the following construction projects risk groups: external
(weather, law, culture, government, customer risk attitudes, etc.), operational (safety,
extemporary site conditions, contractor experience, contractor management, contractor cash
flow, etc.), financial (contractors financial conditions, inflation, delayed payment to
contractors, etc.), engineering (scheduling, productivity, documents not issued on time, etc.)
99
and project management (planning and controlling, decision making, unavailability of
resources, etc.).
To have an effective risk management plan, firstly the critical risk factors which have the
most effect on project objectives should be identified. In order to understand the critical risks
in construction projects in China and to develop strategies to manage them, the researchers
from Australia and China (Zou et al., 2007) realized a postal questionnaire to the Chinese
construction industry practitioners, a statistical analysis of the survey data and a systematic
exploration of identified risks from the perspectives of stakeholders and life cycle. The aim of
the comparative study was to highlight the unique risks associated with construction projects
in China. The purpose of the investigation was not only to generate a list of risks but also to
identify the critical risks that can significantly influence the delivery of construction projects.
On the basis of the data collected by postal questionnaire surveys a total of 25 key risks
influencing the achievement of project objectives in the Chinese construction industry were
ascertained.
The postal questionnaire carried a total of 85 risks associated with construction projects and
asked respondents to review and indicate the likelihood of occurrence of these risks as “highly
likely, likely or less likely” and the magnitude of consequence on each project objective: cost
(C), time (T), quality (Q), occupational safety (OS) and environmental sustainability
(ES) that would result in as “high, medium or low”. The 85 risks were sourced from a wide
range of worldwide literature as well as those specifically focused on the Chinese industry.
After collecting the data from 86 responses, risks were ranked in accordance with their
significance index in association with each project objective, and this is done in turn on the
five categories: cost, time, quality, safety and environmental sustainability respectively. In the
results of the ranking, many risks are repeated among the five categories. For example, “tight
project schedule” can influence all project objectives (cost, time, quality, safety and
environmental sustainability). With the repeated ones filtered, a total of 25 factors were
highlighted as critical risks to impact the project delivery. These risks with their recognized
impacts on project objectives are presented in Tab. 3. The aim of our review of the research
study is to present the survey results, to mention the critical risks of construction projects, we
did not wanted to explain the rationale of the significance index score estimation.
Tab. 3: Critical risks influencing project objectives (Zou et al., 2007)
With significant impact on
The 25 critical risks identified
Tight project schedule
Project funding problems
Variations by the client
Design variations
Inadequate program scheduling
Inadequate site information (soil test and survey report)
Incomplete or inaccurate cost estimate
Contractors` poor management ability
Contractors` difficulty in reimbursement
Poor competency of labourer
Unavailability of sufficient professionals and managers
Without buying insurance for major equipment
Without buying safety insurance for employees
C
T
Q
OS
ES
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
100
Inadequate safety measures or unsafe operations
Lack of readily available utilities on site
Unavailability of sufficient amount of skilled labourer
Prosecution due to unlawful disposal of construction
waste
Serious air pollution due to construction activities
Serious noise pollution caused by construction
Water pollution caused by construction
Low management competency of subcontractors
Suppliers` incompetency to deliver materials on time
Bureaucracy of government
Excessive procedures of government approvals
Price inflation of construction materials
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
Upon the results of the presented study, we estimated the average significance index scores of
different critical risks categories ranked as per their significance on individual project
objective. The scores are following: 0,43 for cost related risks; 0,48 for time related risks;
0,38 for quality related risks; 0,28 for environment related risks and 0,37 for occupational
safety related risks.
The graphical understanding of the average significance index scores of different risk
categories is presented in the radar graph (Fig. 2).
Fig. 2: The average significance index scores of different risk categories
From comparison of the results of two before presented studies (chapter 3: Development
projects – Fig. 1 and Zou et al., 2007 – Fig. 2) is possible to state that the construction project
aspect as time, cost and quality appear to be almost equally eminent in Slovak and in China
construction industry. Unlike, environmental sustainability and occupational safety are
recognized in China research study as more significant aspects having greater impact on
construction projects success.
Similarly, Kuo and Lu (2013) employed a fuzzy multiple criteria decision making approach to
systematically assess risk for a metropolitan construction project. They measured and
investigated the relative impact on project performance of twenty identified risk factors
included in five risk dimensions. Potential risk factors impacting on metropolitan construction
projects were carefully selected and synthesised from the literature review and several expert
interviews. They were classified into five dimensions: engineering design (ED),
construction management (CM), construction safety-related (CSR), natural hazards
(NH), and social and economic (SE).
101
Tab. 4: Overall project risk and individual risk factors (Kuo and Lu, 2013)
Risk factors
Ground water seepage
Typhoon
Conflicting interfaces of work items
Design drawing errors
Heavy rainfall
Increases in prices of construction materials
Inadequate worker safety
Poor construction site surveys
Insufficient protection of adjacent buildings
Earthquake
Poor construction plan
Insufficient experience and skill in construction works
Political interference
Inappropriate design and poor engineering
Protest and interference of nearby residents
Ineffective control and management of traffic
Increases in labours and employee salaries
Delay in relocating existing pipelines and facilities
Ineffective protection of surrounding environment
Unstable supply of critical construction materials
Risk
dimensions
NH
NH
ED
ED
NH
SE
CSR
ED
CSR
NH
CM
CM
SE
ED
SE
CSR
SE
CM
CSR
CM
Estimated
level of risk
0,1047
0,0502
0,0480
0,0471
0,0410
0,0222
0,0216
0,0165
0,0138
0,0138
0,0079
0,0063
0,0056
0,0052
0,0050
0,0050
0,0044
0,0039
0,0030
0,0008
Ranking
order
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
The proposed risk assessment approach was demonstrated using data from a metro system
construction project in the city of Taipei. Five experts with more than fifteen years experience
in construction project management and being familiar with construction project risks were
recruited to participate in the demonstration. The estimated levels of risk for the investigated
risk factors are presented in Tab. 4.
5
CONCLUSION
Regardless of the project size, risk management should be emphasized and implemented in
construction projects, the risk factors are the critical component in achieving project
objectives. Managing risks in construction projects is recognized as a very important process
in order to achieve project objectives particularly in terms of time, cost, quality, safety and
environmental sustainability. To minimise the chances of failure of the construction projects,
the significant risk factors should be properly handled in managing the risks. The model of
integrated building design and delivery of construction project appears as the suitable
situation for early cooperation of clients, designers and contractors in order to manage
potential risks effectively and in time. Mostly, contractors with rich construction as well as
management skills and knowledge could be employed early to reduce construction risks and
make precise preparation for carrying out safe, efficient and quality construction works.
The paper mentioned the projects risks awareness in the construction sector and dealt with the
results of studies intent on determination of critical risks and risk factor in construction
projects as published in the literature. The brief comparison of different studies results
(Slovakia and China) suggests the very similar perception of critical risks in construction
projects and importance of the risks appreciation.
102
Acknowledgements
The article presents a partial result of project VEGA nr. 1/0840/11 Multi-dimensional
approaches supporting integrated design and delivery of construction projects.
References
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2.
3.
4.
5.
6.
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BALOI, D., PRICE, A.D.F. Modelling global risk factors affecting construction cost
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system for cosntruction project management. Nehnuteľnosti a bývanie, 2 (2), 2007.
pp 12-19.
DIKMEN, I., BIRGONUL, M.T., HAN, S. Using fuzzy risk assessment to rate cost
overrun risk in international construction projects. International Journal of Project
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industry. International Journal of Project Management, Vol.26 (4), 2008. pp 431438.
KUO, Y.Ch., LU, S.T. Using fuzzy multiple criteria decision making approach to
enhance risk assessment for metropolitan construction projects. International Journal
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s. ISBN 978-80-86364-13-5.
LAM, K.C., WANG, D., LEE, P.T.K., TSANG, Y.T. Modelling risk allocation
decision in construction contracts. International Journal of Project Management,
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TAROUN, A. Towards a better modelling and assessment of construction risk:
Insight from a literature review. International Journal of Project Management, 2013.
Article in press.
WANG, J., YUAN, H. Factors affecting contractors` risk attitudes in construction
projects: Case study from China. International Journal of Project Management, 29,
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projects in China. International Journal of Project Management, Vol. 25 (6), 2007.
pp 601-614.
Contact
Ing. Zuzana Struková, PhD.
Technical University of Košice, Faculty of Civil Engineering
prof. Ing. Mária Kozlovská, PhD.
103
Technical University of Košice, Faculty of Civil Engineering
104
PRÍKLADY STAVEBNÝCH TECHNOLÓGIÍ PRE BÝVANIE
SOCIÁLNE VYLÚČENÝCH SPOLOČENSTIEV
EXAMPLES OF THE CONSTRUCTION TECHNOLOGIES FOR
HOUSING THE SOCIALLY EXCLUDED COMMUNITIES
Eva Jankovichová
Abstrakt
Politika sociálneho bývania na Slovensku nie je v posledných desaťročiach prioritou žiadnej
vlády a neboli realizované ani zásadné zmeny, ktoré by otvorili možnosti pre jej efektívnejšie
a účinnejšie zabezpečovanie. Bez vysporiadania pozemkov, nie je možné začať proces
legalizácie existujúcich stavieb, nie je možné realizovať ďalšie stavby do budúcnosti (či už sa
jedná o nájomné byty nižšieho štandardu, alebo individuálnu bytovú výstavbu), nie je možné
ani budovanie infraštruktúry. S realizáciou bývania pre sociálne vylúčené spoločenstvá úzko
súvisia stavebné technológie. Niekoľko príkladov bude obsahovať aj predkladaný príspevok.
Kľúčové slová: sociálne bývanie, sociálne vylúčené spoločenstvá, nájomné byty nižšieho
štandardu, stavebné technológie
Abstract
Social housing policy in Slovakia is not a priority in recent decades, and any government or
implemented by fundamental changes that would open up opportunities for its efficient and
effective ensuring. Without the settlement of land, it is not possible to begin the process of
legalization of existing buildings, it is not possible to implement additional buildings in the
future (whether it is a rental housing lower standard, or individual housing construction), you
can not even build infrastructure. With the implementation of housing for socially excluded
communities also are connected closely the construction technologies. Some examples would
include the present contribution.
Key words: social housing, socially excluded communities, rental housing lower standard,
construction technologies
ÚVOD
Sociálne vylúčené spoločenstvo (SVS) je sídelné zoskupenie uvedené v zozname SVS,
tvorené fyzickými osobami, ktorých životné podmienky definované v tomto zákone vedú k
vysokej miere sociálnej deprivácie (chronické neuspokojovanie potrieb) a spoločenského
znevýhodnenia a celkovému zníženiu životných šancí.[1]
Takto je definované SVS v legislatívnom zámere pripravovaného zákona o sociálne
vylúčených spoločenstvách z dielne Ministerstva práce, sociálnych vecí a rodiny (MPSVR)
SR.
105
Obr. č. 1: Rozdelenie z hľadiska sociálnej práce
1 SOCIÁLNE BÝVANIE
Súčasná definícia sociálneho bývania sa nachádza v zákone 443/2010 o dotáciách na rozvoj
bývania a o sociálnom bývaní, ktorý vymedzuje sociálne bývanie takto:
„Sociálne bývanie je bývanie obstarané s použitím verejných prostriedkov určené na
primerané a ľudsky dôstojné bývanie fyzických osôb, ktoré si nemôžu obstarať bývanie
vlastným pričinením a spĺňajú podmienky podľa tohto zákona. Sociálne bývanie je aj bývanie
alebo ubytovanie financované s použitím verejných prostriedkov a poskytované v rámci
starostlivosti podľa osobitných predpisov.“[2]
Verejný nájomný sektor by mal slúžiť predovšetkým pre zabezpečenie sociálneho bývania, a
teda by mal byť využívaný takými obyvateľmi, ktorí si nemôžu obstarať bývanie na voľnom
trhu. Z uvedeného dôvodu by mal tento sektor fungovať na princípe neziskovosti, aby
hospodárenie s ním nebolo stratové, ale zároveň aby takéto bývanie bolo cenovo dostupné.
Nájomné v tomto sektore by malo pokrývať všetky náklady spojené s obstaraním a
prevádzkou nájomných bytov pri rešpektovaní princípu čo najnižšej obstarávacej ceny.
Rešpektovanie týchto princípov si vyžaduje, aby bolo takéto bývanie ponúkané obcami a
neziskovými organizáciami s priamou alebo nepriamou účasťou finančných zdrojov štátu pri
jeho výstavbe.
Koncepcia štátnej bytovej politiky zároveň obsahuje ambíciu aby sociálne bývanie bolo v
ďalšom období legislatívne definované podľa určitých technických, ekonomických a
sociálnych kritérií, aby bolo jednoznačne identifikovateľné.
Do kategórie sociálneho bývania možno zahrnúť:
● nájomné byty vo verejnom nájomnom bytovom sektore vrátane malometrážnych bytov
určených napr. ako prvé bývanie pre mladé rodiny s tým, že nárok na takéto bývanie budú
mať len domácnosti do stanovenej výšky príjmov;
106
● byty a iné formy bývania pre domácnosti s nízkymi príjmami a skupiny so špecifickými
potrebami, ako napr. byty pre občanov v sociálnej núdzi, s ťažkým zdravotným postihnutím,
osamelých rodičov starajúcich sa o maloleté deti, mnohodetné rodiny, občanov po ukončení
ústavnej alebo ochrannej výchovy, občanov s problémami sociálneho začlenenia a občanov
bez prístrešia;
● byty nižšieho štandardu pre marginalizované skupiny obyvateľstva;
● byty pre bývanie starších ľudí, ktorých výstavbu budú koordinovať vyššie územné celky,
pričom pri spôsobe financovania a pri výbere budúcich užívateľov sa bude vychádzať z
majetkových pomerov budúcich užívateľov.
Vzhľadom na cieľ zákona o SVS v oblasti bývania je potrebné zvoliť 2 základné smery
politík a aktivít, ktoré povedú k:
■ rozptylu koncentrovanej chudoby, obmedzeniu getoizácie a integrácii obyvateľov SVS do
väčšinovej spoločnosti
■ zlepšeniu existujúcich podmienok bývania v lokalitách definovaných ako SVS.
Bývanie v SVS je možné charakterizovať prevažne vysokou koncentráciou, teritoriálnou
odlúčenosťou od hlavných sídiel, veľkým počtom ľudí žijúcich na malej ploche, existenciou
nelegálnych príbytkov, svojpomocnou realizáciou stavieb nízkeho technického štandardu a
nedostatočnou infraštruktúrou vybavenosťou. 46 osídlení je evidovaných v kritickom stave,
bez akejkoľvek technickej infraštruktúry, t.j. vodovodu, kanalizácie, plynu a spevnenej
prístupovej cesty.[3]
Graf č. 2: Typy sociálneho bývania [4]
107
2
PRÍKLADY STAVEBNÝCH TECHNOLÓGIÍ - SLAMA, DREVO, HLINA
2.1 Prvý slamený dom na svete, Hrubý Šúr, Slovensko
Autorom experimentálnej stavby je nemecký architekt a emeritný profesor univerzity v
Kasseli Gernot Mink, ktorý za pomoci špeciálneho počítačového programu vypočítal presné
rozmery slamených tvárnic, ktoré mali hmotnosť 120 kg / m³ a ktoré sa dokonale podľa vzoru
narezali a pospájali. Vznikol tak prvý samonosný dom zo slamy na svete.
Jedinečná stavba v malej dedine Hrubý Šúr neďaleko Senca na juhozápade Slovenska má
osem klenieb a uprostred kupolu s priemerom šesť metrov. Jej perfektná pevnosť by mala
odolať dokonca aj zemetraseniu. Stavba vyžaduje minimálne vykurovanie. Slama je totiž
nielen nosná, ale má aj vynikajúce izolačné vlastnosti. To si majitelia stavby už overili, dom
má za sebou už tri zimy. Stavať sa začalo v auguste 2010 a celá stavba trvala asi deväť
týždňov. Ďalší čas strávili majitelia dokončovacími prácami.
Lisované slamené balíky sú vo vnútri aj zvonku omietnuté hlinou. Práve hlina zvyšuje
ochranu pred požiarmi. Hlinené omietky sú v interiéri jemné a dekoratívne. V exteriéri bola
hlinená omietka zaizolovaná, pokrytá geotextíliou a na ňu bola navezená miestna pôda, na
ktorej pomaly rastie zelená strecha. Hlinené sú aj podlahy, ktoré majitelia ošetrili náterom a
olejovým voskom.
V dome s rozlohou 65 metrov štvorcových sídli architektonické štúdio Createrra, ktoré sa
špecializuje na energeticky pasívne domy. Každý jednotlivý výklenok má vlastnú funkciu. V
prvej je vstupné zádverie, na ktoré nadväzuje klenba s kuchynkou.. V ďalších klenbách sú
pracovné miesta orientované do všetkých svetových strán. Uprostred je spoločný funkčný
priestor. Interiér štúdia je zariadený čisto a jednoducho bežným nábytkom.
Náklady na stavbu sú takmer nevyčísliteľné. Investori k celému projekt pristúpili alternatívne
a kupolu vybudovali svojpomocne.[5]
2.2 Hlineno-slamený dom, Spišské Podhradie, Slovensko
Experimentálny projekt výstavby hlineno-slameného domu chce dosiahnuť atribúty využitím
stavebných materiálov, ktoré sú skutočne z miestnych zdrojov a miestnej produkcie. Ide o
materiály, ktoré sú trvanlivé, odolné, navyše kvalitné, lacné, ekologické a ich použitie pri
samotnej výstavbe je jednoduché a nenáročné, takže sa do nej môžu zapojiť aj budúci
nájomníci či vlastníci. Hlineno-slamený dom v Spišskom Podhradí tvorí drevená konštrukcia,
t.j. drevené stojky a drevené strešné väznice, ktoré sú vyplnené lisovanými slamenými
108
balíkmi, zavetrené drevenými latami a omietané hlinenou omietkou. Slamené balíky slúžia
ako tepelnoizolačná výplň v murive, podlahe i streche. Tento stavebný materiál má veľmi
veľkú životnosť a je využitý ako výplňový /nie nosný/ materiál pre drevenú stĺpovú
konštrukciu, ktorá zabezpečuje nosnosť strechy. Využitie slamených balíkov je teda veľmi
jednoduché, úsporné a výstavba veľmi rýchla. Dom zo slamy má dobrú izoláciu a vďaka
hlineným omietkam dostatočnú odolnosť voči ohňu.
Keďže sú slamené bloky pevne stlačené, nemajú dostatok vzduchu na to, aby došlo k horeniu.
Objem múrov hlineno-slameného domu umožňuje pohltiť veľké množstvo tepla a jeho
obyvateľ tak môže výrazne usporiť tepelnú energiu. Taktiež údržba domu je pre obyvateľov
hlineno-slameného domu nenáročná. Okrem uvedených výhod je slama dostupným a najmä
obnoviteľným materiálom, ktorý sa dá „vypestovať“ za rok a v našej krajine je vlastne
materiálom odpadovým. To, čo sa každoročne spáli tak možno maximálne zhodnotiť
použitím na výstavbu cenovo dostupných obydlí. Na výrobu slamených balíkov sa však musí
použiť slama dobre vymlátená, vysušená a čerstvo zlisované bloky je dobre postriekať
vápnom proti hmyzu a hlodavcom.[6]
ZÁVER
Typickými stavebnými materiálmi boli v minulosti na Slovensku práve drevo, hlina a slama.
Na základe štúdia tradičných slovenských spôsobov výstavby a v súčasnosti realizovaných
pilotných projektov, je reálne sa k nim opäť vrátiť.
Ministerstvo výstavby a regionálneho rozvoja SR vypracovalo v roku 2006 vzorové projekty
cenovo dostupných bytových domov nižšieho štandardu aj s návrhom materiálových
variantov. Medzi odporúčanými stavebnými materiálmi sú betón, štiepkocementové dosky,
penový polystyrén, penosilikátové tvárnice, monolitický železobetón, vápenná alebo
vápenno-cementová omietka, olejový náter, plastové okná, cementové podlahy, hydroizolačné
strešné fólie, tepelno-izolačné panely z čadičovej vaty, sadrokartón a.i.
Použitá literatúra
1. VÁVROVÁ, B.: Sociálne vylúčené spoločenstvo ako jeden z konceptov. [online]
publikované
10.06.2011.
[citované
15.09.2013].
Dostupné
z
http://www.sfpa.sk/dokumenty/pozvanky/685
2. Dlhodobá koncepcia bývania pre marginalizované skupiny obyvateľstva a model jej
financovania. [online] publikované 2005. [citované 25.01.2013]. Dostupné z
http://www.build.gov.sk/mvrrsr/index.php?id=17&cat=266&comment=2317
3. Postupy prípravy a vzorové projekty výstavby bytov nižšieho štandardu. [online]
publikované 2006. [citované 14.09.2013]. Dostupné z http://www.build.gov.s
k/mvrrsr/?id=10&cat=237&news=2379
4. SUCHALOVÁ, A., STAROŇOVÁ, K.: Mapovanie sociálneho bývania v mestách
Slovenska. [online] publikované 2010. [citované 21.01.2013]. Dostupné z
http://www.fses.uniba.sk/fileadmin/user_upload/editors/uvp/Socialne_byvanie_publik
acia.pdf
5. Prvý slamený dom na svete postavili na Slovensku. [online] publikované 2010.
[citované 14.09.2013]. Dostupné z http://www.dobrenoviny.sk/c/6923/video-prvyslameny-dom-na-svete-postavili-na-slovensku
109
6. Slameno – hlinený dom v Spišskom Podhradí. [online] publikované 03.04.2008.
[citované 14.09.2013]. Dostupné z http://slamahlina.blogspot.sk/2008/04/hlinenoslamenn-dom-ako-alternatva-k.html
Príspevok bol spracovaný v rámci grantovej výskumnej úlohy VEGA 1/0184/12.
Kontaktné údaje
Doc. Ing. Eva Jankovichová, PhD.
Slovenská technická univerzita v Bratislave, Stavebná fakulta, Katedra technológie stavieb
Tel: +421-2-5927 4221
110
INFORMATION TECHNOLOGIES AND EFFECTIVE INFORMATION
FLOWS IN SELECTION OF SUB-CONTRACTORS OF
CONSTRUCTION WORKS
Tomáš Mandičák, Peter Mesároš
Abstract
In the contribution are mapped information flows that arise in the construction process among
the participants in this process and also defines the participants of construction. The use of
ICT is conducive to the efficient use of sources in each enterprise. The resource efficiency in
construction is also very important selection of subcontractors for construction work. The
contribution includes model ASAP, which is the basis for the selection of subcontractors. This
system is linked to the enterprise information system of contractor. ASAP model is a decision
support tool for selection of appropriate subcontractor based on selected criteria.
Key words: information flows, the participants of construction, ASAP model
1
INTRODUCTION
The economic crisis in recent years has hit almost all the sectors involved in the country's
GDP. One of the hardest hit areas is construction industry. Many projects have been
suspended or their scope is eliminated. The process of construction is extended, in the worst
cases, completely suspended. This situation occurred despite the fact that nowadays it is
possible to use new technologies that increase productivity. The whole construction process is
faster and easier. The construction industry faces many challenges at the beginning of the 21st
century as it is forced to change and to incorporate new advanced technologies into the
construction process to gain a competitive edge in the market [1].
The construction industry has multidisciplinary character, relying heavily on the timely
transmission of information between interested parties, such as owners, project managers,
design consultant, contractors, subcontractors and suppliers [8].
For more effective construction process, timely and reliable information are essential for
participants. Their content, relevancy, timeliness, and the ability to share real-time greatly
assist in the construction process. The realization of buildings, which can be defined as
construction activities transforming (reshaping) the inputs to production outputs, is more
efficient with the help of appropriate information management, resulting mainly in saving
resources, costs and time [9].
2
PARTICIPANTS IN THE CONSTRUCTION PROCESS AND THE
RELATIONSHIPS BETWEEN THEM
The potential of use of ICT in construction projects is great. Each stage of the project requires
a large amount of information that must be available for particular audiences. The same is true
in the implementation phase of construction. Particularly suitable for the use of intermediate
inputs (construction materials, construction equipment, employees, energy), which in the
process are transformed into new buildings, buildings. Interaction of the fundamental factors
arising from the implementation of the final product construction - construction work [9].
The building project can be defined as direct participants [3]:
• user of construction work - has priority status in defining requirements,
111
•
•
•
•
builder,
investor,
designer,
contractor.
Intervener participants (indirect) are [10]:
• construction supervision,
• construction authority,
• other participants (owners of adjacent land, banks, local authorities).
This subdivisions of participants is associated with the investment process, but realization of
the construction brings close cooperation between them and operative solution of those
problems. Thus arise between them close relationships and information flows. In these
processes can then enter the building manager, who also reviewed some impact on facility
management. These participants as well as the relations between them are shown in fig. 1.
Fig. 1/ Participants in construction, and relationships between them
The relationship between the contractor between sub-contractor is very important. The
amount arises flows towards both ways. Good communication between the participants must
be automatic. Important is the actual process of selecting sub-contractors who are actively
involved in construction work. Also on effective communication and selection between subcontractors and suppliers standing a construction project.
3
INFORMATION FLOW IN PROCESS OF SELECTING SUBCONTRACTORS
Nobody would deny that proper management of information brings in value. The value is
obtained when information enables people and systems to efficiently perform actions and
make decisions. The purpose is to understand the information flow that takes place throughout
the construction process during at every stage. Managing information is not just information
processing in pure system terms but also includes decision making by various actors involved
in enhancing the information flow [11].
112
The need to improve information flow has long been recognized in design management
research. A common approach is to begin by modeling the processes and mapping the flows
of information using techniques and languages such as data flow diagrams (DFD), unified
modeling language (UML), structured analysis and design technique (SADT), integrated
definition methods (principally IDEF0) and others [4].
Information flow consist of four components: source of information, receiver of information,
a path (interaction), and a mutual relevance of information. There are two types of entities that
can serve as sources or receivers of information [7]:
•
•
People - everybody involved in process of generating, acquiring, sharing and using
information. A person’s role in information flow is determined by their contractual
role, their informal technical role, and their social role within the project. These roles
determine the types of information that are expected from a person, the type of
information that the person can contribute, how that information is shared, and how it
is received.
Boundary objects (i.e. tools such as drawings, reports, building information models,
requests for information, and other documents that enable communication between
groups of people). Boundary objects affect information flow through their structure.
Information flow is a two-way transfer of information between two entities (parties) possible
in a certain time (perfect real time) for which the information is relevant and have explanatory
power [5].
Especially in the construction process or realization stage is a large number of participants,
particularly within suppliers or sub-contractors. They must be timely informed about what
they are doing. Information flow must be faster to each sub-contractor possessed relevant
information, to perform the further decisions. Relevance and speed of information is very
important not only in the strategic planning, but mainly for operational planning, which is in
the implementation phase of construction necessary.
Due to the speed with which most projects are carried out, most subcontractors are selected
only when the time for their portion of the work is near, to the point that the time used for
giving out contracts becomes excessively short; aside from hastiness and the difficulty in
making the best choice, recognition and communication may not be adequate, and this can
easily lead to conflicts between subcontractors on the site [2].
For operational planning in a building project is important to address the availability of the
latest information. Usually in every project is the prime contractor that uses multiple subcontractors. For this case it is appropriate to use the model ASAP.
ASAP model does not address only the issue of information sharing, but also the selection of
sub-contractors in short term. On this basis, if necessary, can quickly choose a suitable
operational sub-contractor for a specific amount of work. At this stage it greatly speeds up the
process and thus the time.
Of course, it is necessary to address this superstructure on the base platform, which is based
on basic information systems enterprise, ERP system. The question of compatibility and data
exchange is necessary. During the construction of the necessary information flows are
reduced.
4
ASAP MODEL
The ASAP model is provided with the functions of real-time decision making and endowed
with capabilities similar to the Internet bidding market. Due to the potential for a high number
113
of subcontractors on the market, every business usually employs a certain kind of software
system to manage and record documents and information e.g. MS Word, Lotus WordPro or
Adobe PDF format.
The ASAP model comes out of the theory of information technology integrated with quick
response mechanisms of e-commerce, puts to use statistics and investment portfolio theory,
takes all of the possible subcontractor combinations of bidding information into consideration
and finally analyzes it as an expenditure loading distribution curve. This model assumes that
[6]:
•
for each project, the general contractor plans logical relationships between
subprojects;
•
all parties offering and competing for bids have already been pre-qualified and
recognized as qualified subcontractors;
•
the decision-making process considers the selection of subcontractors to be a process
of investment portfolio, and each combination of subcontractors represents one certain
kind of portfolio set in the market. ASAP model will automatically estimate the
relative risk versus its profit according to specific Arisk basisB, which is assigned by
the decision-maker at the beginning of subcontracting simulation.
The figure 2 shows the process of selecting a subcontractor on the basis of pre-selected
criteria. The whole process is simpler and faster. Individual subcontractors, however, must be
preapproved in advance and if their choice will be accepted. Based on this model, and the use
of technology is the construction process faster and in many cases less costly due to the rapid
selection of a suitable subcontractor [6].
An important aspect of using this model is to define criteria for the selection of subcontractors. This system is intended to support decision-making selection sub-contractors can
do more than just choose the optimal combination of sub-contractors, multiplied by the risk
preferences of the decision maker. This system provides more options and criteria functions
such as choice of sub-contractor with the lowest price, with the lowest cost in the shortest
time.
ASAP model consists of three-layer architecture, which is often used in recent years. This
architecture combines the advantages of concentration and client-server structure. The
advantage is the separation of the user interface to model business logic and reduces
dependency between an application program and data. This is a very flexible and efficient
structure for data update. Every user must open your browser through which you can get all
necessary information online [6].
114
Fig. 2 / Schematic representation of ASAP approach for selection [6]
The figure 3 shows the process of exchanging information and also information flows that
arise at this stage of the project. Also, the essential information and communication are
shown, respectively principle on which the system operates.
The basis of ASAP model is that it works from the perspective of the main contractor. He
must prepare the documents necessary for the adoption of a specific offer by the subcontractor. Important is also the location of the call to sub-contractors aware of the challenge.
Since it is already approved before the sub-contractors are therefore largely bonds between
them and this information is timely aware. Sub-contractors and complete the necessary forms
with the specific offer. Through the system will record these offers. System based on the
criteria evaluate each offer and provide support for the decision on the selection of suitable
sub-contractors. ASAP model is linked with enterprise systems (ERP) prime contractor.
115
Fig. 3/ The information flow of ASAP system [6]
CONCLUSION
In every stage of the construction project is an amount of information that is essential to
manage. Their efficiency can positively influence each project. Firstly the cost and therefore
the economic side, as well as time. For their effective use, information and communication
technologies that enable information acquisition, sharing and availability in real time. are
essential. This advantage is also necessary in the implementation phase of the building
project. At the same time, at this stage it is necessary and quick selection of sub-contractors
who have been preapproved in previous stages, the specific work that is not always already
planned in previous stages. For these situations is used ASAP model, which defines the
process and flow of information when selecting pre-approved in advance of subcontractors in
the execution stage. This paper describes the flow of information in a given model, which
represents a systemic solution as an extension of the already established information system
in the enterprise.
Acknowledgements
Article is the result of the Project implementation: University Science Park TECHNICOM
for Innovation Applications Supported by Knowledge Technology, ITMS: 26220220182,
supported by the Research & Development Operational Programme funded by the ERDF. We
support research activities in Slovakia/This project is being co-financed by the European
Union.
116
The paper is partial output of the project VEGA 1/0840/11 "Multi-dimensional approaches to
support integrated design and management of construction projects."
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Address
Ing. Tomáš Mandičák,
doc. Ing. Peter Mesároš, PhD.
117
ZKUŠENOSTI S APLIKACÍ MECHANO-CHEMICKY
AKTIVOVANÝCH MATERIÁLŮ PRO ÚPRAVU VLASTNOSTÍ
POPÍLKOVÝCH SMĚSÍ
EXPERIENCE WITH THE APPLICATION OF MECHANOCHEMICALLY ACTIVATED MATERIAS USED IN FLY-ASH MIXES
Václav Mráz, Jan Suda, Jan Valentin, Miloš Faltus
Abstrakt
Produkty z procesu spalování a odsíření (zejména různé typy popílků) lze využít jako materiál
k vytváření zemních konstrukcí dopravních staveb. V dopravním stavitelství je v současné
době používáno menší množství těchto produktů, než je jejich skutečný výskyt. Jednou z
možných příčin, limitujících použití některých typů popílků zejména ze spalování hnědého
uhlí, je relativně malá odolnost při opakovaném kontaktu s mrazem a vodou, kdy dochází
k výskytu nežádoucích jevů. Proto v rámci experimentálních měření byla v popílkových
směsích standardně používaná aditiva nahrazena alternativním anorganickým sypkým
pojivem, získaným mechano-chemickou aktivací (mikromletím) fluidních popílků a
dolomitického vápence.
Klíčová slova: popílek, mechano-chemicky aktivované materiály, zemní konstrukce
dopravních staveb, mrazuvzdornost
Abstract
Products gained during coal combustion and desulphurization (especially different types of
fly-ashes) can be used as materials for construction of roadbed structures. In transport
infrastructure presently lower amount of these products is used in comparison to the available
amount. One of the possible reasons, which are limiting use of some types of fly-ashes
especially from soft-coal combustion, is their relatively low resistance against repeated frost
and water immersion. During this cycling undesirable effects occur which limit the durability
of the structure. Therefore within ongoing research chemo-mechanically activated fly-ash
from fluidized combustion and activated dolomitic lime have been used in fly-ash mixes. The
activated microfiller replaced traditional inorganic additives or binders used regularly.
Key words: fly-ash, mechano-chemically activated materials, roadbed structure, freezing and
water immersion
1
ÚVOD
Mechano-chemicky aktivované materiály vznikají vysokorychlostním a obecně
vysokoenergetickým mletím. V celosvětovém měřítku probíhá v této oblasti poměrně
intenzivní výzkum či vývoj a v některých oborech přináší již dnes významné ekonomické i
environmentální úspory. Hlavním přínosem této skupiny technologických procesů je, že
umožňuje kvalitativně nové využití stávajících surovin nebo využití takových materiálů, které
pomocí jiných technologií upravit nelze. Tento princip bylo snahou převzít též na různé typy
popílků. Používání popílkových stabilizátů, fluidních popelovin a dalších tuhých produktů
spalování a odsíření má dobré předpoklady pro využití do zemních konstrukcí dopravních
staveb. Díky své nižší objemové hmotnosti a vysoké smykové pevnosti, snižují při stavbě
zemní konstrukce sedání podloží i tlak na opěrné konstrukce. Jednou z možných skutečností
118
limitujících použití některých typů popílku je relativně malá odolnost při opakovaném
kontaktu s mrazem a vodou a vykazování objemových změn.
Vzhledem k výše uvedeným negativním vlastnostem popílku, které se vyskytovaly především
při opakovaném účinku mrazu a vody, byla v rámci experimentální činnosti věnována
pozornost zkoušce odolnosti popílkových směsí proti mrazu a vodě, která může rozhodnout o
použití nebo nepoužití popílkové směsi. Byly navrženy popílkové směsi z technologie
fluidního spalování s ověřením aplikace mikro-mletého (mechano-chemicky aktivovaného)
fluidního popílku a dolomitického vápence. V dalším kroku se předpokládá též ověření
funkčnosti obdobně aktivovaného betonového recyklátu.
2
METODICKÝ A KONCEPČNÍ PŘÍSTUP
Pro ověření vlastností popílků byla na katedře silničních staveb Fakulty stavební ČVUT v
Praze u posuzovaných popílkových směsí stanovena zpracovatelnost, pevnostní
charakteristiky a vzhledem k negativním výsledkům při opakovaném styku s mrazem a vodou
byla provedena zkouška odolnosti proti mrazu a vodě.
V rámci experimentálních měření byla v popílkových směsích z elektrárny Ledvice (dále jen
ELE) standardně používaná aditiva nahrazena anorganickým sypkým pojivem, získaným
mechano-chemickou aktivací fluidních popílků a mletého dolomitického vápence.
Efekt mechanické (mechano-chemické) aktivace materiálů je dosažen u mnoha látek pomocí
vysokoenergetického mletí, které se využívá ke zjemnění zrnitosti a ke zvětšení měrného
povrchu řady sypkých látek [1]. Použití mechano-chemicky aktivovaných anorganických
materiálů v různých průmyslových odvětvích může do budoucna přinést řadu nových
možností zvýšení kvality výrobků, přípravy materiálů s novými vlastnostmi či vyšší přidanou
hodnotou, vytvoření nových aplikací či využití v nových odvětvích a pro nové účely.
K mechano-chemické aktivaci se využívají upravené postupy mletí materiálů. Jedním ze
směrů, který se v posledním období intenzivně rozvíjí, je vysokoenergetické mletí.
Vysokorychlostní mletí lze potom chápat jako jeden z typů vysokoenergetického mletí, které
se vyznačuje velkým množství předané energie na jednotku upravovaného materiálu v rámci
procesu mletí. Pojem vysokoenergetického ani vysokorychlostního mletí není nikde v
literatuře přesně definován. S mletím v klasickém pojetí má společné všechny základní
vlastnosti, o kterých bylo výše pojednáno, tedy zjemnění zrnitosti, zvětšení měrného povrchu,
otevření zrn atd. Na rozdíl od klasického mletí při vysokoenergetickém i vysokorychlostním
mletí dochází k určitým jevům (efektům), které nebyly pozorovány u běžného mletí. A právě
na tyto efekty je přeměněna určitá část vynaložené energie, která se u běžného mletí bez
užitku přemění na teplo. Tyto jevy jsou u anorganických materiálů například:
- mechanochemická (mechanická) aktivace,
- tvorba vyšších podílů mikronových částic a nanočástic,
- v některých případech vyšší efektivita využití spotřebované energie na tvorbu nových
povrchů.
Technologie s využitím mechano-chemicky aktivovaných materiálů se aktuálně ověřuje při
nahrazení části cementu v betonech či maltách a při úpravě zemin. Tento princip byl snahou
převzít i pro úpravu vlastností popílku s cílem vylepšit technické parametry.
2.1 Mechano-chemicky aktivované materiály (pojiva)
Mechano-chemicky aktivovaný fluidní popílek je suché anorganické hydraulické pojivo,
vyrobená pomocí vysokorychlostního mletí na bázi vedlejšího energetického produktu, tj.
popílku z fluidního spalování tuhých fosilních paliv a dalších přísad.
119
V lomu Krty u Strakonic jsou těženy metamorfované horniny jihočeské větve Moldanubika,
převážně amfibolity a krystalické vápence. Amfibolity samotné, nebo ve směsi s
krystalickými vápenci a dalšími minoritními horninami jsou využívány na výrobu drceného
kameniva. Krystalické vápence kalciticko – dolomitického složení jsou využívány pro výrobu
bílého hrubého a jemného drceného kameniva pro stavební a zemědělské účely.
Hlavní na lokalitě zastoupené horniny tvoří v lomu polohy a čočky o mocnosti od několika
metrů až do více než 10 metrů. Hlavní horniny jsou pronikány žilnými horninami, zejména
pegmatity. Relativně malá mocnost jednotlivých poloh a čoček vápenců a amfibolitů
neumožňuje dostatečně efektivní selektivní těžbu těchto hornin. Pro zajištění vytřídění
kvalitní bílé vápencové suroviny je na ložisku provozována linka na optické třídění. Drcení
surovin a jejich třídění na jednotlivé frakce drceného kameniva je následně zajištěno
mobilním drtícím zařízením. V následujících tabulkách jsou uvedeny rozbory drceného
vápencového kameniva.
< 20 µm
20 – 50
50 – 80
80 -250
250 – 400 400 - 800
µm
µm
µm
µm
µm
4,55%
8,35%
5,76 %
21,71 %
14,59 %
23,51 %
hmot.
hmot.
hmot.
hmot.
hmot.
hmot.
Tab. č. 1 Výsledky granulometrického rozboru neupraveného vzorku na sítech
+800 µm
21,53 %
hmot.
< 20 µm
20 – 50
50 – 80
80 -250
250 – 400 400 - 800
+800 µm
µm
µm
µm
µm
µm
94,47 %
4,96 %
0,57 %
0
0
0
0
hmot.
hmot.
hmot.
Tab. č. 2 Výsledky granulometrického rozboru aktivovaného dolomitického vápence na sítech
Counts
Calcite, magnesium, syn
xx vap Krty nemlety.CAF
Calcite, magnesium, syn; Ferroactinolite
Calcite, magnesium, syn; Talc-2\ITM\RG; Ferroactinolite
Dolomite; Ferroactinolite
Dolomite
Dolomite
Dolomite; Talc-2\ITM\RG
Dolomite
Ferroactinolite
Dolomite
Talc-2\ITM\RG; Ferroactinolite
Calcite, magnesium, syn; Talc-2\ITM\RG
Calcite, magnesium, syn; Chlorite-serpentine
Talc-2\ITM\RG; Ferroactinolite
Dolomite
Chlorite-serpentine
Chlorite-serpentine; Ferroactinolite
Chlorite-serpentine
Talc-2\ITM\RG
Ferroactinolite
Chlorite-serpentine
2500
Dolomite
10000
0
10
20
30
40
50
Position [°2Theta]
Obr. 1 Práškový XRD záznam vzorku krystalického vápence z lomu Krty
< 0,5 µm
0,5 – 1 µm
1 – 10 µm
10 -20 µm
20 – 40 µm
> 40 µm
2,3 %-hm.
5,3 %-hm.
60,4 %-hm.
25,0 %-hm.
6,4 %-hm.
0
Tab. č. 3 Výsledky granulometrického rozboru aktivovaného dolomitického vápence pomocí
laserového granuloemtru
120
Ref. číslo
01-089-1304
00-005-0622
00-052-1044
00-029-1493
00-045-1342
Název složky
Dolomite
Chlorite-serpentine
Talc-2\ITM\RG
Ferroactinolite
Výskyt
Total
Lines
Faktor
SemiQuant
[%]
64
56
28
21
12
12
13
8
12
43
0.799
0.285
0.003
0.018
0.011
66
29
2
2
Tab. č. 4 Vyhodnocení fázového složení vzorku na základě XRD záznamu
XRD záznam, zhotovený 15 dnů po pokusné úpravě ukázal určité odlišnosti ve fázovém
složení vzorku, zejména destrukci (pravděpodobně dehydrataci) struktury podřadně
zastoupeného minerálu mastku (talc). Při úpravě vysokorychlostním mletím při zvoleném
režimu ale nedochází k mechanochemické dekarbonataci materiálu a fázové složení vzorku se
prakticky nemění. Lehce deformovaný tvar (velmi slabé rozšíření) difrakčních píků minerálu
dolomitu svědčí o posunech a vzniku poruch ve vnitřní struktuře části materiálu a ke vzrůstu
jeho volné entalpie a tedy o jeho výrazné mechanochemické aktivaci i po relativně dlouhé
době skladování.
Ref. číslo
Název složky
Výskyt
Total
Lines
Faktor
SemiQuant
[%]
01-089-1304
01-075-1656
01-074-1758
00-022-0712
Dolomite
Dickite
Nimite
62
62
0
28
12
17
92
19
0.941
0.302
0.003
0.002
71
28
-
Tab. č. 5 Vyhodnocení fázového složení vzorku mletého vápence na základě XRD záznamu
Lze předpokládat, že velmi jemně mletý kalciticko – dolomitický krystalický vápenec ložiska
Krty by mohl být využíván pro účely výroby plniv platických hmot, papíru a barev nebo jako
částečná náhražka portlandského slinku pro výrobu LA – cementů a jako aktivní plnivo pro
studené asfaltové recykláty či asfaltobetony. K prokázání využitelnosti pro každý z výše
uvedených účelů by bylo nezbytné provést řadu zkoušek v příslušných specializovaných
laboratořích [2].
3. ÚČINKY ÚPRAVY MECHANO-CHEMICKY AKTIVOVANÝMI
MATERIÁLY (POJIVY)
3.1 Zkouška zhutnitelnosti popílku
Laboratorní zkouška zhutnitelnosti popílku představuje významnou zkoušku pro posuzování
jeho použitelnosti v dopravním stavitelství. Zhutnitelnost popílku souvisí s tvarem a velikostí
částic. Zhutnitelnost směsí se provedla standardní Proctorovou zkouškou dle ČSN EN 132862 [3]. Hutnění se zahájilo s prodlevou od zvlhčení směsi, která modeluje zadržení
transportem, rozhrnování a další manipulaci při reálném ukládání směsi.
Z výsledků zkoušek zhutnitelnosti fluidního ložového popela z ELE vyplývá, že optimální
vlhkost se pohybovala okolo 35 %, s přidáním 6 %-hm. mletého dolomitického vápence
vykazoval optimální vlhkost 36 % a s 10 %-hm. mletého fluidního popílku potom 38 %.
2.2 Pevnost v prostém tlaku
Laboratorní zkouška pevnosti v prostém tlaku byla provedena podle ČSN EN 13286-41 [4],
při níž zkušební těleso tvaru rotačního válce bylo namáháno rostoucím osovým napětím σ do
porušení. Podstatou zkoušky bylo zatěžování zkušebního tělesa z vytvrzených popílkových
121
směsí jednoosým tlakem za současného měření deformace. Pozornost byla věnována
pevnostním charakteristikám po různé době zrání.
Z popílkových směsí byla v laboratoři hutněním zhotovena zkušební tělesa o rozměrech
R=100 mm a výšce 120 mm. Zkušební tělesa zrála 7, 14, 21, 28, 60 a 90 dní (u některých
směsí i 1 rok) v laboratorním prostředí v neprodyšném obalu. U zkušebního tělesa byla
stanovena i okamžitá pevnost po nahutnění, kde připravený vzorek zrál při laboratorní teplotě
20-23°C cca 2-3 hodiny.
Získané výsledky zkoušek pevnosti v prostém tlaku z ELE jsou uvedeny v obr. 2.
4500
4250
4000
3750
Pevnost v prostém tlaku[ KPa ]
3500
3250
Fluidní ložový popel Ledvice bez aditiv
3000
2750
2500
Fluidní ložový popel Ledvice + 10%
mletý fluidní popílek
2250
2000
1750
Fluidní ložový popel + 6 % mletý
dolomitický vápenec
1500
1250
1000
750
500
250
0
2 - 3 hod. 7
14
21
28
6o
Stáří popílkové směsi [ dny ]
90
365
Obr. 2 Přehled pevností v prostém tlaku hutněných popílkových směsí
Z obr. 2 je patrné, že nejlepších hodnot pevnosti v prostém tlaku dosahují směsi, kde je
zastoupen mletý (mechano-chemicky) aktivovaný fluidní popílek a mletý dolomitický
vápenec, a tudíž tyto směsi splňují minimální požadované hodnoty pro pevnost v prostém
tlaku podle TP 93 [5]. Mletý (mechano-chemicky) aktivovaný fluidní popílek a mletý
dolomitický vápenec prověřil míru substituce hydraulických pojiv těmito materiály.
3.3 Odolnost proti mrazu a vodě
Příprava zkušebních těles a způsob zrání těles probíhalo stejně jako u zkoušky pevnosti v
prostém tlaku. Po dokončení 28 denního zrání se zkušební tělesa umístila na plstěnou
podložku částečně ponořenou ve vodě a nechala se kapilárně nasytit do ustálené hmotnosti
tak, aby přírůstek hmotnosti po dobu nejméně 1 hodiny nepřekročil 1 %. Všechna zkušební
tělesa se kapilárně nasytila během 20 minut od položení na plstěnou podložku.
Následně se zkušební tělesa umístila do mrazící skříně na dobu 6 hodin při teplotě -20°C až 22°C. Po zmrazení se zkušební tělesa z mrazící skříně vyjmula a uložila na dobu 18 hodin
opět na plstěnou podložku částečně ponořenou ve vodě, aby bylo umožněno jejich další
kapilární sycení. Současně s tím probíhalo rozmrazování při teplotě +20°C až +25°C.
Zkouška pokračovala novým zmrazením a opakovala se v 10 cyklech dle postupu uvedeném
v národní příloze ČSN EN 14227-5 [6]. Po skončení posledního cyklu se provedla zkouška
pevnosti podle ČSN EN 13286-41 [7].
122
Obr. 3 Stabilizát z ložového popela z ELE bez aditiv
Stabilizát z fluidního ložového popela z ELE bez aditiv (viz obr. 3) při druhém cyklu vykázal
příčnou trhlinu, cca po 4 hodinách zmrazování ve druhém cyklu se těleso roztrhlo.
Obr. 4 Stabilizát z ložového popela z ELE + 10 %-hm.
mletý fluidní popílek
U stabilizátu z fluidního ložového popela s přidáním 10 % - hm. mechano-chemicky
aktivovaného fluidního popílku se po 10 cyklu vytvořila příčná trhlina (viz obr. 4).
123
Obr. 5 Stabilizát z ložového popela z ELE + 6 %-hm.
mletý dolomitický vápenec
Stabilizát z fluidního ložového popela s přidáním 6 % - hm. mechano-chemicky aktivovaného
dolomitického vápence (viz obr. 5), který byl namáhán odstupňovaným počtům cyklů
zmrazování a rozmrzování vykázal dokonce vyšší pevnost než původní pevnost v tlaku. Tyto
hodnoty je potřeba na dalších sadách vzorků opakovaně ověřit.
4. ZÁVĚR
V předkládaném příspěvku je věnována hlavní pozornost odolnosti stabilizátů připravených z
tuhých produktů spalování a odsíření z elektrárny Ledvice proti mrazu a vodě.
Získané výsledky potvrdily, že vyzrálý stabilizát s použitím mletého fluidního popílku příp.
mletého dolomitického vápence dosahuje poměrně vysokých hodnot pevnosti v prostém tlaku
a je z hlediska geotechniky plně vyhovující.
Stabilizáty připravené z fluidního ložového popela bez aditiv z elektrárny Ledvice je v zásadě
možné použít pro stavby zemních konstrukcí dopravních staveb, ale vzhledem k negativním
výsledkům cyklické zkoušky odolnosti stabilizátu vůči zmrazování a rozmrazování a značné
nasákavosti se jejich využití nejeví příliš perspektivní.
Zkouška odolnosti proti mrazu a vodě ukázala, že stabilizát vyrobený ze zhutněné zavlhlé
směsi s přidáním 10 %-hm. mechano-chemicky aktivovaného fluidního popílku nepatrně
zlepšuje charakteristiku odolnosti popílkových směsí proti účinkům vody než stabilizát
vyrobený bez aditiv. Stabilizáty z ELE bez aditiv a i stabilizáty včetně přidání mechanochemicky aktivovaného fluidního popílku tedy nevyhověly požadavkům ČSN EN 14227-14
[8], a proto bude dále nutné provést stanovení namrzavosti podle ČSN 72 1191 [9]. Stabilizát
z ELE s přidáním 6 %-hm. mechano-chemicky aktivovaného dolomitického vápence je
nejméně náchylný k rozpadu a lze zde uvažovat i o snížení množství přidávaného pojiva.
S použitím mechano-chemicky aktivovaných materiálů do popílkových směsí lze eliminovat
některé problémy popílku a ukazuje se možnost téměř úplné náhrady vápna příp. cementu
těmito materiály.
124
Poděkování
Tento příspěvek vznikl v rámci projektu SGS13/125/OHK1/2T/11.
1.
BALÁŽ, P. Mechanochemistry in Nanoscience and Minerals Engineering. Chapter
2, High - Energy Milling, Springer, Hardcover, Netherland, ISBN: 9783540748540.
2.
FALTUS, M. Zpráva o zkušebním vysokorychlostním mletí krystalického
dolomitického vápence z lomu v obci Krty u Strakonic, 2013, HGF VŠB – TU
Ostrava (nepublikovaná zpráva).
3.
ČSN EN 13286-2 Nestmelené směsi a směsi stmelené hydraulickými pojivy - Část 2:
Zkušební metody pro stanovení laboratorní srovnávací objemové hmotnosti a
vlhkosti - Proctorova zkouška, 2011, ÚNMZ.
4.
ČSN EN 13286-41 Nestmelené směsi a směsi stmelené hydraulickými pojivy - Část
41: Zkušební metoda pro stanovení pevnosti v tlaku směsí stmelených hydraulickými
pojivy, 2004, ČNI.
5.
TP 93 Technické podmínky - Návrh a provádění staveb pozemních komunikací
s využitím popílků a popelů, Praha 2011, Ministerstvo dopravy.
6.
ČSN EN 14227-5 Směsi stmelené hydraulickými pojivy – Specifikace – Část 5: Směsi
stmelené hydraulickými silničními pojivy, 2008, ČNI.
7.
ČSN EN 13286-41 Nestmelené směsi a směsi stmelené hydraulickými pojivy - Část
41: Zkušební metoda pro stanovení pevnosti v tlaku směsí stmelených hydraulickými
pojivy, 2004, ČNI.
8.
ČSN EN 14227-14 Směsi stmelené hydraulickými pojivy – Specifikace – Část 14:
Zeminy upravené popílkem, 2008, ČNI.
9.
ČSN 72 1191 Zkoušení míry namrzavosti zemin, 2013, ÚNMZ.
Kontaktní údaje
Mgr. Václav Mráz
České vysoké učení technické v Praze, Fakulta stavební
Thákurova 7, 166 29 Praha 6 - Dejvice
Tel: 723 488 217
Ing. Jan Suda
Tel: 224 354 946
Ing. Jan Valentin, Ph.D.
Tel: 224 353 880
Mgr. Miloš Faltus
Vysoká škola báňská – Technická univerzita Ostrava, fakulta hornicko-geologická,
17.listopadu 15/2172, 708 33 Ostrava-Poruba
125
THE TERMINOLOGY OF TRADITIONAL AND MODERN TIMBER
FRAME STRUCTURES
Barbora Nečasová
Abstract
The technology of timber framing has a long and spectacular tradition throughout Europe.
Almost 85% of timber houses all over the world are built by this technology. It is not a new
technology thus a lot of disappointing issues, such as statics or typical thermal behaviour of
the cladding, have been solved. This paper is focusing on two most important values, strength
and stiffness of the panel wall, which should be monitored during all phases of the building
process. The desirable state of these characteristics can be achieved only by proper
preservation of the frame members and by regular maintenance of the timber structures. For
better understanding short introduction of the historical background same as use of modern
methods is described at the beginning of this paper.
Keywords: timber frame, tradition, advantages and disadvantages, strength, stiffness
1
INTRODUCTION
Timber frame construction is dominant method used all around the world. Almost 85% of
timber houses are built by this way. The method is very simple so even the average manually
skilled person should be able to contribute with their “own hands”. These homes can be
designed in almost any way. It's one of the few construction methods available that provides
incredible level of design flexibility.
Timber framing is a general term for method of construction which uses timber frame as a
base for the structure of the building. The essential members of the timber frame are
horizontal studs and vertical rails together with sheathing. Such a simple structure has to
transmit all vertical and horizontal loads into the foundations. Timber frame structures are
predominantly build from solid timber members which might be replaced by wood based
materials with similar properties e.g. glue laminated structures etc. The external cladding is
usually non-loadbearing and also from wood (or timber) based materials. Although, it is
desirable for the sheathing to be able to contribute to wind resistance, if necessary provide
desirable external appearance and ensure perfect water tightness of the building. [1]
2
HISTORY OF TIMBER FRAME CONSTRUCTION
1.1 Traditional timber frame
Timber frame has been very popular method of construction for dwellings, from cottages to
large manor houses, throughout the Middle Ages (see Figure 1) and into the early 18th century
in Western and Northern Europe and also in North America. Since this method has been used
for thousands of years in many parts of the world there are numerous styles of historic
framing structures. These styles are often categorized by the type of foundation, type of wall
structure, how and where the beams intersect and the use of curved timber or the roof framing
details. Pertinent example can be found in English speaking countries where it is possible to
follow four main types of timber framed buildings as box frame, post and truss, aisled
construction and cruck frame. The heterogeneous development of timber frame have been
adequately described in a survey form Surrey which says: “The buildings would have been
126
architect design but the standard timber frame construction was vernacular, i.e. build by
local carpenter using local materials, depending on supply of timber or lack of stone.” [2]
Figure 1: Borgund Stavkirke - 1180 AD
1.2 Modern methods of timber framing
The design of timber frame walls has change by far since 18th century. Nowadays methods
are based on the principles of using smaller dimensions of solid timber members. New
directions and technology guidelines have been developed from use in North America.
Currently timber frame builders all around the world predominantly uses factory –
manufactured wall frames and roof trusses or in some cases prefabricated wall and roof
panels. There are only a few specialist companies at the market which makes and erects
frames directly on the construction site. [1], [2]
1.2.1
Methods of construction
Though the frame was primarily developed for house building, it is also widely used for
buildings such as hotels, schools, student accommodation, offices and similar structures. The
selection of an appropriate arrangement is an early decision in the design process when the
substantive role of economic and functional issue has to be taken into consideration. TRADA
127
(2008) noted some of the “trendy” methods of modern timber framing which, described
below:
a. Platform frame construction (see Figure 2)
-
Prefabricated small panels
-
Prefabricated large panels
This type of construction is the most commonly used method of timber frame system. Each
storey is framed with floor to ceiling height panels. The floor deck of one floor becomes the
erection platform of the next storey. The walls might be prefabricated in factories (off-site) or
assembled on the construction site (on-site). The prefabricated wall panels can be either small,
approximately 3.6 m in length, easily manhandled into place within safe and healthy
guidelines or large full elevation – width panels positioned onto place by crane. Most
fabricators have developed their own methods of fitting together the components of the timber
frame and are able to offer the full building services to their own design.
Figure 2: Comparison of Platform frame and Balloon frame structure [4]
-
On-site stick built
The platform frame construction can be also built so called on-site. When the panel is
assembled on the construction site and manhandled into place. This alternative sometimes can
be more time consuming and also quite ineffective from economical point of view. As has
been said above there are only few companies which provides assembly this way.
b. Balloon frame construction (see Figure 2)
This method utilizes long continuous framing members (studs) that run from the bottom
rail to the top rail. The intermediate floors are hung inside the wall panel. The method is
currently not very common, although her main advantage is the reduction of cross-sectional
shrinkage of timber in the external wall.
c. Prefabricated volumetric construction (see Figure 3)
Other type of timber frame structure is volumetric construction. This technology
predominantly involves the factory fabrication of simple box units which can form an
128
individual room or larger spaces. The units are usually complete with finishes and services.
However they have to be placed by crane. The method is best suited to repetitive structures as
hotels, offices etc.
d. Post and beam construction (or portal frame construction) (see Figure 3)
This method comprises a loadbearing system of pots and beams with lightweight timber,
heavy timber or glazed infill panels.
Figure 3: Volumetric construction (left), Post and beam construction (right) [5]
3
PROS AND CONS OF TIMBER FRAME BUILDINGS
Everyone who considers building a structural timber frame will almost certainly want to
compare it to the options, predominantly brick and concrete construction. In following
paragraphs the most basic requirements were considered. The aim is to provide constructive
description that will also point out some ‘ugly true’ about timber structures.
3.1 Speed of design proposal and construction
One thing to agree on is that if a prefabricated timber frame is used the time that it takes to
construct a house on site can quicker in compartment with traditionally built house. It usually
takes seven to fourteen days from the arrival of the specialist construction team on
construction site to the frame being erected. “Many of the trades involved in the construction
of a house, such as electricians and plasterers cannot work in exposed weather conditions
and therefore cannot start until the interior is protected from the weather. These trades can
start much earlier in the build programme of a timber frame house, which means that the
building can be finished earlier.” “Houses with all-masonry walls require a longer period for
mortar and plaster on the inside to dry out and this can extend the build time by several
weeks.” [6]
Disadvantage of timber house can be seen in the time spent constructing a prefabricated frame
is shorter, time has to be allowed for it to be designed and made in the factory beforehand,
three months is not unusual. This means that the design has to be finalised as early as possible
and there is a longer wait before work starts on site than is necessary for an all-masonry
house. Also the erection of the frame can be slowed down by unsuitable weather conditions.
Sometimes is it necessary to wait for weeks for better weather (without rain). [6]
129
3.2 Thermal performance
A clear advantage for timber frame construction is that the insulation is contained within the
depth of the structure, so a typical timber wall can be thinner than its masonry equivalent, e.g.
by 50mm. A further difference between masonry and timber walls is how well they retain
heat. [6]
3.3 Noise and Sound Insulation
The easiest protection against too loud noises is to put something solid and heavy in-between
its sources. Solid and heavy materials automatically have an in-built ability to reduce different
types of sound. Masonry walls, usually because of their dead weight, have an advantage over
more lightweight timber.
High level of sound reduction in timber frame houses can be achieved by building two
separate diaphragms with a structural air gap (layer) between them. Also, some kind of sound
absorbent quilt, such as mineral wool, can be placed into this gap. A similar technology can
be applied in the floors (absorbent layer laid right under the floorboards, over the floor joists).
[6]
3.4 Risk of Condensation
Condensation in timber frame structures is typically caused by cooled down warm moist air
usually formed by space heating and activities such as washing and cooking. The moist has a
tendency to move to where the air is drier thus from the inside to the outside of the
construction. In winter this point may occur either on the surface of the walls, windows or
other internal surfaces, or inside the construction. The most effective method to prevent such
an effect is to place a vapour check such as polythene sheet between the inside wall and the
layer of thermal insulation. Such a simple item will not allow any vapour to pass through it.
[6]
3.5 Rot, Fungi and Beetles
It is very unusual for a modern timber frame structures to suffer from rot. External timber
elements, such as cladding and cladding boards inclined to rot due to low maintained however
the timber frame itself is always well-preserved. Wet rot is the most common cause of fungal
attack. On the other side dry rot is typically the one that provokes the most fear and
excitement. In a modern heated house the moisture content will usually settle down at about
12%. Fungi will usually appear if the moisture content in construction is higher than 20%.
Denied its principle requirements of warmth and dampness, rot will never be able to establish
itself. Attack of the frame by insects is similarly unlikely. Every member of timber frame
structure has to be preserve before assembled into the construction. If these rules are followed
usually nothing can infest the structure. [6]
3.6 Green Construction
It is undeniable truth that timber has many environmental benefits which cannot be found in
any other building material. However the philosophy of ‘timber builders’ which should be as
follows: “Timber is said to be ‘renewable’ because, in order to replace it, another tree is
planted. Provided that a similar tree is planted for every one that is felled, the supply is
infinite. This is in stark contrast to bricks, blocks and concrete, all of which rely on the
extraction of raw materials from the earth, which ultimately will run out.”,[6] is also a little
bit crooked. The timber for dwelling structures have to fulfil many requirements and
standards, to find such a tree is getting harder and harder and even more expensive. Timber is
130
ecological and renewable material but we have to have on our minds that to work with it, it is
not that easy as to say.
3.7 Cost
“Cost comparisons are difficult to make between timber frame and other construction
materials. Actual construction costs are probably a few percentage points higher for a typical
timber frame over brick and block. However there are other factors that can affect the cost of
a timber frame that have more to do with the way that the suppliers are chosen than the
actual construction costs. Many timber frames are sold as pre-designed kits, a relatively
expensive way of building whatever the material use, causing timber frame prices appear
high.” [6]
Whilst the costs of a timber kit house may be higher, there is more price certainty. Factory
costs are far more predictable than building costs on site and tend to fluctuate less. Finance
costs may be increased slightly, because unlike a typical builder, who is always paid after
work has been completed, kit suppliers ask for money in advance to cover the off-site
investment that is required. Having to pay earlier means that interest charges are spread over a
long time period and therefore are higher.[6]
3.7.1
4
Consideration of timber frame construction:
- Time pressure e.g. if building in winter
- Poor state of the building subsoil.
- Calm and quite surrounding.
- Good availability of timber in the area.
- Usage of environment friendly materials.
- The design if the building does not require large structural spans and major design
changes are not required in the future.
- A lot of work will be done by unprofessional (unskilled) persons.
- Etc.
CONCLUSION
Timber (wood) has more positive characteristics than any other building material and it is pity
that still so many builders, designers and also people have too many doubts about it. When
taking into consideration to build a house it is important to do a small research about
reasonable possibilities and to get rid of the prejudices.
Sources
1. TWIST H., LANCASHIRE R., Timber frame in action, 4th edition, TRADA
Technology Ltd., 2008. 263 p. ISBN 978-1-900510-56-1
2. GRIFFITHS R.D., The Racking Resistance of timber frame walls assessed by
experimental and analytical techniques, Volume 1st, University of Surrey, 1987. 454 p.
3. KULIKOV S., Agriculture mechanics graphics, Agedweb.org [online] 2008. [citation:
11.10.2013]. Achieved from: http://www.agedweb.org/agmech/TOC.htm
4. Blueprint reading, Schools.ednet.ns.ca, [online] 2008. [citation: 11.10.2013]. Achieved
from:
http://schools.ednet.ns.ca/avrsb/133/ritchiek/notes/Text/grade10/BLUEPRINT%20RE
ADING.htm
5. NEWMAN P., Timber frame – where are we now?, TRADA Technology Ltd. 2002.
[online] 2003. [citation: 11.10.2013]. Achieved from:
http://research.ttlchiltern.co.uk/pif294/tdk/background_resources/timber%20engineeri
131
ng%20technology/structural%20options/where%20are%20we%20now/where%20sma
ll.htm
6. OWEN J., Pros and Cons, Constructionchat.co.uk, [online] 2013. [citation:
11.10.2013]. Achieved from: http://www.constructionchat.co.uk/articles/timberframe-buildings/
Contact
Ing. Barbora Nečasová
Technical University of Brno, Faculty of Civil Engineering
Veveri 331/95, 602 00 Brno
tel: +420 54114 - 8110
132
PRŮJEZDNÁ VZDÁLENOST MOTOROVÝCH VOZIDEL OD
VYHRAZENÉHO JÍZDNÍHO PRUHU PRO CYKLISTY
MOTOR VEHICLE PASSAGEWAY DISTANCE FROM MANDATORY
CYCLE LANE IN THE MAIN TRAFFIC CORRIDOR
Jiří Drbohlav
Abstrakt
Dopravní výzkum průjezdné vzdálenosti motorových vozidel od vyhrazeného jízdního pruhu
pro cyklisty má zásadní význam pro optimalizaci návrhu uličního prostoru s prvky cyklistické
infrastruktury. Výzkum tak dokáže podchytit prvky, které pozitivně i negativně ovlivňují
pohyb motorových vozidel. Nejdůležitější je optimalizace šířky jízdního pruhu pro motorová
vozidla a vyhrazeného jízdního pruhu pro cyklisty.
Klíčová slova: Cyklistická doprava, hlavní dopravní prostor, průjezdná vzdálenost, vyhrazený
jízdní pruh pro cyklisty
Abstract
Transport research of motor vehicles passageway from mandatory cycle lane in the main
traffic corridor has the main importance for optimization of the proposal of street space with
the elements of cycling infrastructure. The research can to catch the elements, which have
positive and negative influence for the cyclists and motor vehicles. The most important is
optimization the width of vehicle lane and cycle lane in the main traffic corridor.
Key words: Cycle transport, main traffic corridor, passageway distance, cycle lane in the
main traffic corridor
1 ÚVOD
Cyklistická doprava je v České republice paradoxně teprve na počátku. Proč paradoxně?
Ačkoliv se jízdní kolo v České republice používá více jak sto let, cyklistická infrastruktura,
která je budována za účelem podpory cyklistické dopravy, neoslavila ještě ani svojí první
dekádu.
Cyklistická doprava je ovšem velmi dynamická a to hlavně z toho důvodu, že jsou přejímány
již vyzkoušené prvky ze zahraničí, které jsou v České republice aplikovány. Prvky a převážně
pak jejich použití je samozřejmě pro Českou republiku specifické a tak se určitému vývoji
nevyhneme.
Nejsou ovšem ze zahraničí přejímány jenom prvky cyklistické infrastruktury, jedná se pak o
celkovou koncepci cyklistické dopravy ve městě ale i v celé České republice. Systémy
značených cyklotras s nadřazenými a podřazenými trasami jsou nezbytnou součástí pro dobře
fungující cyklistickou síť.
Pro dobré fungování cyklistické infrastruktury jsou důležité tyto faktory:
• Cyklistická infrastruktura musí být budována pro cyklisty, nesmí je omezovat, musí je chránit a musí
jim pomáhat
• Cyklistická infrastruktura nesmí primárně omezovat motorovou dopravu (či jinou), ale musí s ní
kooperovat (motorová doprava bude vždy jedna z nejdůležitějších a tak jí neúčelně omezovat zcela
nejde…)
Pro další vývoj cyklistické infrastruktury a aplikaci prvků pro její podporu jsou nezbytné
dopravní průzkumy zachycující chování cyklistů a ostatních účastníků dopravy. Kompletní
133
průzkum chování cyklistů v hlavním dopravním prostoru je dosti složitý, díky velké volnosti
cyklistů. Místo průzkumu jsou spíše aplikovány výsledky vycházejících z osobních
zkušeností. Daleko jednodušší je prozkoumat chování řidičů motorových vozidel vůči prvkům
cyklistické infrastruktury v hlavním dopravním prostoru. Jeden ze zásadních průzkumů je
respektování či nerespektování vyhrazeného jízdního pruhu pro cyklisty v hlavním dopravním
prostoru a zjištění průjezdné vzdálenosti. Právě na tuto oblast byl zaměřen průzkum průjezdné
vzdálenosti motorových vozidel od vyhrazeného jízdního pruhu pro cyklisty. Podobný
průzkum v České republice ještě nebyl proveden. První část průzkumu a jeho výsledky jsou
popsány v tomto článku. Článek je zaměřen na průjezdnou vzdálenost v přímém úseku,
vyhodnocenou dle šířky pruhu pro motorová vozidla.
2 DOPRAVNÍ PRŮZKUM
Dopravní průzkum průjezdné vzdálenosti probíhal na několika úsecích v Praze. Byly to
například komunikace Rohanské nábřeží, Českomoravská, V Olšinách, Vršovická,
Tupolevova aj. Průzkum byl proveden na 27 úsecích s minimálním časem měření 30 minut.
Úseky byly vybírány tak, aby statistický soubor byl věrohodný a postihoval různé parametry
komunikace, jako je geometrie, šířka pruhu pro motorová vozidla, počet jízdních pruhů pro
motorová vozidla, přítomnost podélného parkování atd.
2.1 Metoda měření
Na komunikaci byl připevněn měřící pásek s vyznačenými vzdálenostmi po 5 cm. Pásek měl
délku celkem 150 cm. 100 cm pásku bylo umístěno v jízdním pruhu pro motorová vozidla
(kladná hodnota) a 50 cm v pruhu pro cyklisty (včetně vodorovného dopravní značení záporná hodnota). Nula na měřícím pásku byla umístěna na rozhraní pruhu pro motorová
vozidla a vodorovného dopravního značení oddělující vyhrazený jízdní pruh pro cyklisty.
Obr.1: Měření průjezdné vzdálenosti motorových vozidel
134
Obr.2: Měření průjezdné vzdálenosti motorových vozidel
Měření bylo provedeno pomocí pořízení videozáznamu digitální kamerou a jeho zpětného
vyhodnocení. Vyhodnocení bylo provedeno pomocí počítačového programu, kde je možné
prohlížení jednotlivých framů pořízeného videozáznamu.
Z videozáznamu pak byly vyhodnoceny jednotlivé průjezdné vzdálenosti motorových vozidel
na celých 5 cm.
2.2 Metoda vyhodnocení
Pro jednotlivé naměřené hodnoty pro daný úsek byly stanoveny hodnoty popisné statistiky
(střední hodnota, medián, modus, směrodatná odchylka, rozptyl výběru a další). Dále byly pro
jednotlivé úseky stanoveny hodnoty pro histogram (pro jednotlivou průjezdnou vzdálenost
byla stanovena četnost a kumulativní četnost).
Aby naměřené hodnoty měly vypovídající hodnotu, je nutné jednotlivé měřené profily
rozdělit do kategorií dle parametrů komunikace.
Základní rozdělení je dle směrového vedení komunikace a šířky jízdního pruhu pro motorová
vozidla. Toto rozdělení je pak determinující pro základní statistický soubor dané kategorie.
3 VÝSLEDKY VÝZKUMU
V následující tabulce jsou výsledky popisné statistiky pro jednotlivé šířky pruhů pro motorová
vozidla.
Tab.1: Popisná statistika jednotlivých profilů
PŘÍMÁ
ŠÍŘE 3,00 m
ŠÍŘE 3,25 m
ŠÍŘE 3,50 m
Stř. hodnota
58,04
65,98
64,37
Chyba stř. hodnoty
0,90
0,36
0,64
Medián
60
65
60
Modus
60
65
60
Směr. odchylka
21,11
16,07
18,54
Rozptyl výběru
445,69
258,11
343,82
Špičatost
1,25
1,69
1,74
Šikmost
-0,48
-0,47
-0,50
Minimum
-20
-20
-30
Maximum
100
105
100
135
Součet
Počet
Hladina spolehlivosti (95,0%)
31690
129850
53295
546
1968
828
1,77
0,71
1,26
Na následujících grafech je vyobrazeno normálové rozdělení pravděpodobnosti průjezdné
vzdálenosti pro jednotlivé šířky jízdních pruhů pro motorová vozidla.
Graf.1: Normálové rozdělení, přímá, šířka pruhu pro motorová vozidla 3,00 m
136
Normálové rozdělení bylo provedeno pro všechny souhrnné výsledky daných úseků (přímá
geometrie, šířka pruhu). Tyto výsledky by mohly být špatně interpretovány, protože dávají
souhrnné výsledky pro různé profily komunikací, kde se pro stejnou šířku pruhu pro motorová
vozidla střední hodnota průjezdné vzdálenosti liší i o 20 cm.
Například pro pruh šíře 3,25 m vycházejí střední hodnoty od 61,35 cm (Rohanské nábřeží) do
76,63 cm (Českomoravská).
Vyhodnocení jednotlivých úseků pak bude mít průběh Gaussovy křivky více „špičaté“ než u
souhrnných výsledků, jak je to vyobrazeno na dalším grafu.
Graf.4: Gaussova křivka pravděpodobnosti pro souhrnné výsledky pruhů šířky 3,25 m a Rohanské nábřeží (šířka
pruhu 3,25 m)
Na Gaussovu křivku má vliv směrodatná odchylka, která v tomto konkrétním příkladu má
hodnotu pro „Přímou šíře 3,25 m“ 16,07 a pro „Rohanské nábřeží“ 11,54.
Souhrnné výsledky pro určitou šířku pruhu pro motorová vozidla tak slouží spíše jako
orientační rozsah možné průjezdné vzdálenosti.
137
Na následujícím grafu jsou ukázány jednotlivé křivky pro danou šířku pruhu pro motorová
vozidla.
Graf.5: Gaussova křivka pravděpodobnosti pro jednotlivé souhrnné výsledky šířky pruhů 3,00 m, 3,25 m, 3,50 m
Z grafu je patrné, že pro šířku 3,00 m vychází křivka se střední hodnotou 58,04 cm nejblíže
k pruhu pro cyklisty. Křivka je také více „plochá“, protože motorová vozidla mají méně
prostoru a tak má celkový statistický soubor největší směrodatnou odchylku a to 21,11.
Střední hodnota pro šíři pruhu 3,25 m a 3,50 m vychází prakticky totožně (65,98 cm a 64,37
cm), hlavní rozdíl je pak právě opět ve směrodatné odchylce, která hlavně určuje průběh
grafu. Gaussova křivka pro pruh šíře 3,50 m je na první pohled paradoxně „plošší“ než pro
pruh šíře 3,25 m. Tento závěr je ovšem zcela logický a je to z důvodu velkého rozptylu
středních hodnot jednotlivých měření – například pro komunikaci Tupolevova je tato hodnota
56,50 cm a 84,44 cm pro komunikaci Milady Horákové.
Z grafu je tedy patrné, že šířka pruhu pro motorová vozidla má minimální vliv na průjezdnou
vzdálenost. Při zvětšení pruhu o 0,25 m se zvětší průjezdná vzdálenosti o cca 6 cm, to samé
pak platí i pro zvětšení 0,5 m. Rozšiřovat tak pruh pro motorová vozidla, aby byli více
ochráněni cyklisté od projíždějících motorových vozidel, má minimální účinek. Daleko
účinnější by tak bylo rozšířit samotný pruh pro cyklisty. Tento fakt je podpořen i samotnými
výsledky, kde průzkum ukázal, že například pro komunikaci Tupolevovu (šíře 3,50 m) je
střední hodnota 56,50 cm a pro komunikaci Chotkova (3,00 m) 61,15 cm. Na průjezdnou
vzdálenost má pak větší vliv samotný celkový návrh komunikace a vedení komunikace než
samotná šířka jízdního pruhu.
Chybovost při vyhodnocení měření bylo provedeno pomocí zaokrouhlení výsledků na celých
„10“ dolu a nahoru.
Tab.2: Základní hodnoty popisné statistiky (naměřené výsledky, zaokrouhlené výsledky na celých „10“ nahoru a
dolu
PŘÍMÁ
ŠÍŘE 3,00 m
ŠÍŘE 3,25 m
ŠÍŘE 3,50 m
Stř. hodnota
58,04 (55,72) (60,20)
65,98 (63,48) (68,48)
64,37 (62,48) (66,26)
Medián
60 (60) (60)
65 (60) (70)
60 (60) (60)
Modus
60 (60) (60)
65 (60) (70)
60 (60) (60)
Směr. odchylka
21,11(21,22) (21,18)
16,07 (16,48) (16,14)
18,54 (18,78) (18,62)
Červené hodnoty jsou pro zaokrouhlení dolu, modré pro zaokrouhlení nahoru. Výsledky pak
byly zpracovány do následujícího grafu, který zachycuje Gaussovu křivku průjezdné
138
vzdálenosti pro jednotlivé šířky jízdních pruhů pro motorová vozidla včetně zaokrouhlených
hodnot.
Graf.6: Gaussova křivka pravděpodobnosti pro souhrnné výsledky, včetně zaokrouhlení výsledků na celých „10“
nahoru a dolu
4 APLIKACE VÝSLEDKŮ
V současnosti slouží pro návrh jízdního pruhu pro cyklisty technické podmínky TP179,
norma ČSN 73 6110 a pak metodická pomůcka pro vyznačování pohybů cyklisty v hlavním
dopravním prostoru vytvořená Komisí pro cyklistickou dopravu v Praze. Tato pomůcka stará
více jak 4 roky je stále platná a aktuální a v jistých směrech i nadčasová. Byla několikrát
upravena a úpravy vycházely z osobních zkušeností z pohledu cyklisty v hlavním dopravním
prostoru samotných tvůrců.
Metodická pomůcka pro funkční skupiny intravilánových komunikací B (sběrné komunikace)
a C (obslužné komunikace) uvažují s šířkou pruhu pro cyklisty 1,50 m a šířku 3,00 m pruhu
pro motorová vozidla. Metodická pomůcka neuvažuje s intenzitou motorové dopravy.
139
Obr.3: Pomůcka pro návrh prvků cyklistické infrastruktury, zdroj: ČSN 73 6110, 2006
Pro určení vedení cyklistů v hlavním či přidruženém dopravním prostoru slouží obrázek
z normy ČSN 73 6110. Ten určuje dle rychlosti a intenzity motorové dopravy, kde mají být
cyklisté vedeni. Při rychlosti motorového vozidla 50 km/hod a intenzitě vyšší než 20 tis.
vozidel/24hod (v obou směrech) by už měli být cyklisté vedeni v přidruženém dopravním
prostoru. Tato grafická pomůcka je v současnosti už překonaná a projektanti se dle ní neřídí.
Při správném návrhu uličního prostoru není problém pro cyklisty pohyb v hlavním dopravním
prostoru spolu s dalšími účastníky dopravního provozu při jakékoliv intenzitě. Například na
Rohanském nábřeží v Praze s intenzitou cca 18 tis. vozidel/24hod (v jednom směru) integrace
cyklistů v hlavním dopravním prostoru dobře funguje. Norma ČSN 73 6110 pro funkční
skupinu B a C pak určuje šířku pruhu pro motorová vozidla 3,25 m.
Právě na Rohanském nábřeží je jízdní pruh pro motorová vozidla přilehlý k pruhu pro cyklisty
(1,75 m) široký 3,00 m (místy i 3,25 m).
Z průzkumu jasně vyplývá, že pro přilehlý pruh k vyhrazenému jízdnímu pruhu pro cyklisty
v hlavním dopravním prostoru stačí šíře 3,00 m. V případě předpokládaných vyšších intenzit
dopravy je pak účelnější rozšířit pruh pro cyklisty. Na následujícím obrázku jsou upraveny
předpokládané šířky pruhů pro cyklisty dle intenzity dopravy motorových vozidel v jednom
směru a předpokládané rychlosti motorových vozidel. Pro rychlost do 30 km/hod je budování
vyhrazeného jízdního pruhu pro cyklisty v hlavním dopravním prostoru neúčelné. Při
předpokládané intenzitě do cca 2500 vozidel/24hod je pohyb cyklistů v pruhu pro motorová
vozidla bezkonfliktní. S narůstající intenzitou motorové dopravy a rychlosti vozidel je účelné
zvětšit pruh pro cyklisty pro jejich zvýšenou bezpečnost. Při rychlosti vozidel 30 km/hod
předpokládáme rozdíl rychlosti mezi vozidlem a jízdním kolem do 15-20 km/hod. Naopak při
rychlosti 50 km/hod již tento rozdíl může mít hodnotu 25-40 km/hod. Tyto velké rozdíly
v rychlostech pak jsou pro cyklisty nepříjemné a jistým způsobem je vnímají jako
potencionální nebezpečí.
140
Obr.4: Návrh úpravy šířky jízdního pruhu pro cyklisty dle intenzity motorové dopravy
5 ZÁVĚR
Důležitý závěr z dopravního výzkumu je, že motoristé v drtivé většině případů respektují pruh
pro cyklisty.
Graf.7: Střední hodnoty průjezdných vzdáleností jednotlivých profilů
Výsledky dopravního průzkumu jasně ukázaly, že rozšiřování pruhu pro motorová vozidla za
účelem větší separace cyklistů od motorových vozidel v hlavním dopravním prostoru je více
méně bezúčelné.
141
Na předchozím grafu jsou střední hodnoty pro jednotlivé měřené úseky. Červené hodnoty
jsou pro pruh šíře 3,50 m, modré pro šířku 3,25 m a zelené pro 3,00 m. Z grafu je patrné, že
střední hodnoty pro různé profily se prolínají a neplatí fakt, že čím větší pruh pro motorová
vozidla, tím větší průjezdná vzdálenost.
Jak již bylo psáno, pro průjezdnou vzdálenost je důležitější samotný návrh komunikace jako
celku, než se pouze soustředit na šířku pruhu pro motorová vozidla.
PODĚKOVÁNÍ
Příspěvek byl realizován za finančního přispění Studentské grantové soutěže ČVUT, 2013,
Číslo FIS: 161-830480A000
1.
Kolektiv autorů, ČSN 73 6110, Praha: Český normalizační institut, 2006. 128 stran.
2.
Komise pro cyklistickou dopravu RHMP, Metodická pomůcka pro vyznačování
pohybu cyklistů v HDP. 2009-05, Praha – Komise pro cyklistickou dopravu RHMP,
2009. 12 stran
Kontaktní údaje
Ing. Jiří Drbohlav
České vysoké technické učení v Praze, Fakulta stavební
Thákurova 7, 166 29, Praha 6
Tel: 607 566 738
email: [email protected], [email protected]
142
UKOTVENÍ OKENNÍCH RÁMŮ NA NOSNOU KONSTRUKCI
LEHKÉHO OBVODOVÉHO PLÁŠTĚ OD-001 „BOLETICKÝ PANEL“ S
OHLEDEM NA TEPELNÉ NEPRAVIDELNOSTI
ANCHORAGE WINDOW FRAMES TO THE SUPPORTING
STRUCTURE OF CURTAIN WALLING OD-001 "BOLETICKY
PANEL" DUE TO THERMAL IRREGULARITIES
Pavel Liška
Abstrakt
Článek se zabývá problematikou technologie ukotvení nových okenních rámů do původní
nosné konstrukce lehkého obvodového pláště budov OD-001 „Boletický panel“. V dnešní
době se velmi často přistupuje k revitalizaci zmíněných konstrukcí a je vhodné se zamyslet
nad polohou okenních výplní s ohledem na tepelnou techniku. Při využiti materiálů se
stejnými tepelně technickými vlastnosti, především tepelné izolace stejné tloušťky, lze s
různými konstrukčními variantami dosáhnout odlišných lineárních tepelných nepravidelností.
Jak v oblasti připojovací okenní spáry, tak i v původní nosné konstrukci obvodového pláště.
Klíčová slova: okenní rám, nosná konstrukce, ukotvení
Abstract
The article deals with a technology of anchoring new window frames into the original
structure of the lightweight cladding of buildings OD-001 "Boleticky panel". Nowadays, we
revitalize these structures and it is worthwhile to consider the placement of windows with
focus on the thermal engineering. When materials with the same thermal and technical
properties are used, above all thermal insulation of the same thickness, we can obtain different
linear thermal irregularities.
Key words: window frame, structure, anchoring
1
PŮVODNÍ KONSTRUKCE OD-001 „BOLETICKÝ PANEL“
Konstrukce OD-001 “Boletický panel“ byla v tehdejším Československu nejvíce realizovaný
předsazený obvodový plášť panelového typu s nosnou rámovou konstrukcí. Jeho výroba
začala už v letech 1960 až 1961 v Závodech stavební prefabrikace, n. p. Boletice u Děčína,
který se stal zároveň největším producentem v celém Československu. V osmdesátých letech
jeho výrobní kapacita činila kolem sto tisíc metrů čtverečních konstrukce za rok (pětadvacet
tisíc panelů). V průběhu let se do výrobního programu zapojovaly další podniky např.
Pozemní stavby, n. p. Bratislava nebo Zukov, n. p. Praha [4].
Konstrukce se vyznačovala malou vhodností pro objekty s velkými požadavky na hygienu
např. školky. Proto se konstrukce využívala zejména pro administrativní objekty, kulturní
domy či pošty. Maximální výška objektu směla být 100 m nad úrovní terénu [2]. Jeho
základní technické parametry jsou uvedeny v Tab. 1.
143
Popis
Hmotnost panelu
Skladebná šířka
Skladebná výška
Skladebná tloušťka
Výška okna
Výška podokenní části
Průměrný tepelný odpor panelu celého panelu
Součinitel prostupu tepla v netransparentní části
Součinitel prostupu tepla v transparentní části
Průměrný tepelný odpor nepravidelností
Vzduchová propustnost oken
Relativní zvuková neprůzvučnost panelu
Požární odolnost panelu
Jednotka
kg · m-2
mm
mm
mm
mm
mm
m2·K·W-1
W·m-2·K-1
W·m-2·K-1
m2·K·W-1
m2·s-1·Pa-1
dB
s (min)
Hodnota
50
600, 900, 1 200, 1 500
3 300, 3 600
90
1 600, 1 800
1 000
2,020
0,496
3,498
0,533
0,620
25
1920 (32)
Tab. 1 Základní technické parametry LOP OD-001 „Boletický panel“ [4], [5], [6]
Základní skladebná šířka u běžných panelů je 0,6; 0,9; 1,2 a 1,5 m, skladebná výška 3,3 a 3,6
m (atikové panely 3,6; 3,9 a 4,2 m). Nosný rám panelu je tvořen v případě obvodové a střední
příčle uzavřeným tenkostěnným profilem průřezu 90x40 mm a tloušťce 2 mm, parapetní a
nadpražní příčle byly prováděny z profilu U. V netransparentní (neprůhledné) části pláště je
vnitřní povrch stěn buď z dřevotřískových desek, nebo z azbestocementových desek o
tloušťce 15 mm (v závislosti na požadavcích protipožární ochrany). Za těmito deskami je
minerální tepelná izolace nebo pěnové sklo o tloušťce cca 60 až 80 mm v ochranném
plastovém obalu. Tato tepelná izolace je buď zakryta azbestocementovou deskou, nebo
kovovým roštem. Z důvodu kondenzace vzdušných par je navržena větraná vzduchová
mezera. Sklo, které tvoří vnější povrch, je buď opaktní nebo smaltované a to vždy v tvrzené
formě. Připevnění tohoto skla k nosné rámové konstrukci je pomocí hliníkových lišt.
Transparentní (průhledná „okenní“) část je tvořena buď dřevěnými, ocelovými či hliníkovými
okny nebo jejich kombinací. Zasklení je zdvojené, nebo z izolačních dvojskel. Ve svislé spáře
jsou k sobě panely připevněny svěrnými spoji. Zakrytí těchto spojů je z venkovní strany
realizováno hliníkovými lištami a z vnitřní strany stejným materiálem, jako je vnitřní
opláštění „azbestocementová nebo dřevotřísková deska“. Ve vodorovné spáře jsou panely
k sobě připevňovány tzv. přeplátovanými spoji, kdy dolní panel je překryt okapem, který je
součástí panelu nad ním. Připevnění panelů k nosné konstrukci je řešeno prostřednictvím
kotevních háků (dva dolní a dva horní), které jsou součástí panelů na svislicích. (Obr. 1) [2],
[3], [4], [5].
144
Obr. 1 Pohled na lehký montovaný plášť budovy OD-001 „Boletický panel“ [3]
Na následujícím infračerveném snímku je ukázáno na rozsáhlé tepelné nepravidelnosti, které
vznikají v oblastech nosného rámu mezi jednotlivými panely, ale i okenních výplní.
Povrchová teplota v těchto místech klesá pod teplotu, kdy dochází ke kondenzaci vodní páry,
ale i k růstu plísní. Tento defekt má negativní vliv na samotnou konstrukci, ale i lidí
pobývajících uvnitř objektu.
Obr. 2 Infračervený termosnímek (dále jen IČT) na
lehký obvodový plášť OD-001 „Boletický panel“ z
vnitřní strany [3]
2
Obr. 3 Snímek viditelného spektra k IČT Obr. 2 [3]
REVITALIZOVANÁ KONSTRUKCE OD-001 „BOLETICKÝ
PANEL“
V současné době existuje mnoho způsobu, jak se dají tyto konstrukce revitalizovat. Každá
stavební společnost, projektant či dodavatel stavby, zabývající se touto problematikou, má
svoje vlastní konstrukční řešení. Jedná se ale o ověřené systémy, které se ve velkém množství
aplikují ve stavební výrobě. V následujícím textu je poukázáno na možnosti ukotvení
okenního rámu na původní nosnou konstrukci v případě revitalizace se zachováním funkčních
celků, které se běžně provádějí.
Objekty po revitalizaci mají nesrovnatelně menší tepelné nepravidelnosti (lineární i bodové)
než v případě původní konstrukce OD-001 „Boletický panel“, a to především díky lepším
145
tepelně technickým vlastnostem, vyřešením návazností na ostatní konstrukce a odstranění
špatných konstrukčních detailů.
2.1 Možnosti ukotvení
Pro zhodnocení jednotlivých variant je vytvořeno šest 2D modelů v softwaru Stavební fyzika
– Area 2010. Způsob revitalizace původního opláštění OD-001 „Boletický panel“ je vždy
stejný, aby byla zachována možnost jejich srovnání. Sledované parametry těchto 2D modelů
jsou průběhy teplot v konstrukci a povrchové teploty při vnitřním povrchu původní nosné
konstrukce. Jestliže v konstrukci nastane taková situace, kdy teplota klesne pod rosný bod,
dochází ke kondenzaci vodní páry. Tento kondenzát zhoršuje tepelně technické parametry,
může způsobit postupnou degradaci konstrukce a růst plísní, které jsou škodlivé pro lidské
zdraví.
Modely vychází ze způsobu revitalizace systémem sádrovláknitých desek od společnosti
Fermacell GmbH. V tomto konkrétním případě je uvažováno, že při vnitřním povrchu nejsou
azbestocementové desky, ale dřevotřískové, které jsou nahrazeny sádrokartonem. Všechny
okenní výplně, vnější klempířské a upevňovací prvky jsou odstraněny včetně vnějšího
tvrzeného skla, které slouží jako ochranná vrstva a pro vytvoření provětrávané vzduchové
mezery. Následně jsou osazeny nové okenní výplně a na původní nosnou konstrukci opláštění,
která byla vyztužena je připevněna sádrovláknitá deska. Na takto připravený podklad se
následně připevní (lepící tmel + talířové kotvy) izolant tloušťky 140 mm. Nakonec se osadí
všechny klempířské prvky, provede výztužná vrstva tkaniny do tmelu a finální povrchová
úprava ze silikonové probarvené omítky. Upevnění okenního rámu k nosné konstrukci je
uvažováno systémem kotevních šroubů přímo skrz okenní rám do nosné konstrukce, nebo
prostřednictvím kotveních úhelníků, které jsou ukotveny do nosné konstrukce.
Vnější klimatické okrajové podmínky jsou navrhnuty pro teplotní oblast -15 °C s relativní
vlhkostí vzduchu 84 %. Vnitřní teplota vzduchu je 20,6 °C s relativní 50 %.
Velikosti modelů vycházejí ze zásad pro posuzování detailů z hlediska tepelně technických
parametrů, tj. v těchto případech jsou modely navrženy vždy do poloviny transparentní i
netransparentní části dvou sousedních panelů.
2.2 Numerické modely
Ukotvení okenního rámu při vnitřním líci nosné konstrukce
V prvním případě (Obr. 4) se jedná o plastové okno s dvojsklem, rámem tloušťky 76 mm
a pěti komorami. Okenní rám je umístěn k vnitřnímu líci nosné konstrukce. Povrchová teplota
12,32 °C v místě původní nosné konstrukce je ze všech modelových případů nejnižší a
pohybovala se těsně nad hranicí požadovanou nornou ČSN 73 0540-2 tj. 11,59 °C. V případě
výplně otvorů má teplota hodnotu 7,82 °C. V tomto případě není požadovaná minimální
povrchová teplota dle této normy splněna tj. 8,25 °C. Na povrchu okenní výplně by se tvořila
kondenzace vodní páry [1].
146
Obr. 4 Ukotvení okenního rámu při vnitřním líci nosné konstrukce [7]
Ukotvení okenního rámu při vnějším líci nosné konstrukce
Ukotvení okenního rámu při vnějším lící nosné konstrukce má při zachování stejného typu
okenní výplně, jako v prvním případě pozitivní vliv povrchovou teplotu v místě původní
nosné konstrukce (Obr. 5). Teplota v tomto místě se zvýší o 1,35 °C, V případě okenní výplně
zůstává požadovaná minimální povrchová teplota pod požadavky normy.
Obr. 5 Ukotvení okenního rámu při vnějším líci nosné konstrukce [7]
Ukotvení okenního rámu před líci nosné konstrukce
Vyložení okenní výplně před nosnou konstrukci směrem do venkovního prostředí mělo
nesrovnatelně lepší dopad na konstrukci z hlediska povrchových teplot u nosného rámu
opláštění než v předchozích případech. Jak je znázorněno na Obr. 6 povrchová teplota
v těchto místech se zvýšila při stejných okrajových podmínkách o 1,81 °C oproti druhé
variantě na 15,48 °C, kdy okenní rám byl umístěn k vnějšímu líci nosné konstrukce.
V případě umístění při vnitřním licí nosné konstrukce to bylo o 3,16 °C.
Obr. 6 Ukotvení okenního rámu před líci nosné konstrukce [7]
Ukotvení okenního rámu tloušťky 90 mm na nosnou konstrukci
Jak ukazují předchozí případy okenní výplně s dvojsklem, v dnešní době přestávají být
vyhovující a přechází se na okenní výplně s trojskly. Pomalu, ale jistě to začíná být
147
standardem a většina investorů uvažuje nad touto možností. Okenní výplně s trojskly
potřebují masivnější rámy. Rámy tloušťky 76 mm, které se navrhují pro dvojskla, jsou
nevyhovující jak z hlediska šířky, tuhosti, tak i svými tepelně technickými parametry.
V následujících dvou případech je použit šesti komorový okenní rám tloušťky 90 mm s třemi
těsněními mezi tímto rámem a rámem křídla. Jelikož šířka nosné konstrukce je stejná jako
tloušťka okenního rámu, konstrukce lícují na obou stranách. Povrchová teplota u nosného
rámu je stejná jako v druhém případě, kdy okenní rám lícuje s nosnou konstrukcí na vnitřní
straně. Významný tepelně technický posun je v místech transparentní části okenní výplně
(Obr. 7). Povrchová teplota u distančního rámečku je o 3,12 °C vyšší než požaduje norma.
Obr. 7 Ukotvení okenního rámu tloušťky 90 mm na nosnou konstrukci [7]
Ukotvení okenního rámu tloušťky 90 před líc nosné konstrukce
Poslední varianta (Obr. 8), kdy je okenní výplň zcela vyložena před nosnou konstrukci a
zároveň se použilo trojsklo je ideální kombinací z hlediska tepelně technický vlastností.
Povrchová teplota transparentní i netransparentní části obvodového pláště vysoce překonává
požadavky norem. U transparentní části o 3,43 °C a u netransparentní části o 4,21 °C.
Obr. 8 Ukotvení okenního rámu tloušťky 90 před líc nosné konstrukce [7]
2.3 Reálný stav
Na infračerveném termosnímku je ukázán skutečný stav tepelných nepravidelností, které
vznikají v místech nosného rámu obvodového pláště. V tomto případě je okenní rám ukotven
přímo na nosnou konstrukci po celé jeho šířce. Jedná se o plastové okno s tloušťkou rámu 90
mm o šesti komorách. Rám je opatřen dekompresní komorou na vnější straně a s třemi
těsněními mezi rámem okna a okenního křídla. Zasklení je z trojskla. I když se nejedná o
stejný způsob revitalizace jako v případě 2D modelů, následující snímek ukazuje na lineární
tepelné nepravidelnosti, které vznikají v místech původní nosné konstrukce. Revitalizace
původní konstrukce je provedena systémem plechových kazet od společnosti DEKMETAL,
s.r.o.
148
Obr. 9 IČT snímek na vnitřní povrch opláštění,
ukotvení rámu okenní výplně tloušťky 90 mm na
původní nosnou konstrukci OD-001 „Boletický panel“
Obr. 10 Snímek viditelného spektra k IČT snímku
Obr. 9
Tab.: 1 Parametry k IČT snímku Obr. 9
Popis
Emisivita
Teplota vnitřního vzduchu
Zdánlivě odražená teplota
Vlhkost vnitřního vzduchu
Vzdálenost
Dle ČSN EN 13187
Rozdíl teplot mezi vnějším a vnitřním prostředím během zkoušky
Rozdíl vnějších teplot 24 hodin před zahájením zkoušky
Rozdíl vnitřních teplot během zkoušky
Rozdíl vnějších teplot během zkoušky
Rychlost větru
Teplota bodu změřená dotykovým teploměrem
Poznámky:
Zataženo
Otopná tělesa – vypnuta 24 hodin před měřením
Použité zařízení Termokamera FLIR E30bx
3
Jednotka
°C
°C
%
m
Hodnota
0,96
22,10
21,40
26,70
2,68
°C
°C
°C
°C
m/s
°C
26,5
6,00
3,80
1,70
0,4
17,10
ZÁVĚR
Numerické modely i skutečný stav ukazují, že skutečně záleží na konstrukčním řešení a ne
pouze na použitých materiálech. Další významnou kapitolou je i kvalita provedených prací.
Jestliže máme zvolen dobrý konstrukční systém a zároveň jsou použity kvalitní materiály,
může dojít při neodborném provedení k vytvoření tepelným nepravidelnostem takového
rozsahu, že případná náprava může být nákladnější než samotná revitalizace původní
konstrukce. Na následujícím snímku je poukázáno na tepelnou nepravidelnost, která vznikla
v místech okenního rámu, kde od realizace v roce 2006 nedošlo k údržbě kování a tím
dochází po delší čas k únikům tepla z objektu (Obr. 11).
V případě rozhodnutí investora, že uskuteční revitalizaci opláštění OD-001 „Boletický panel“
či jiné obvodové konstrukce, je nutné si zajistit zkušeného a odpovědného projektanta z
oblasti tepelné techniky. V rámci projektu by měl navrhnout několik variant konstrukčních
řešení a následně v závislosti na finančních nákladech nechat rozhodnout investora
s odborníkem na danou problematiku. Ve stavebnictví a zejména u obvodových plášťů
neplatí, že nejlevnější řešení je zároveň to nejlepší.
149
Základem dobrého projektu je dostatečné množství a kvalita propracování detailů. Bez nich
realizační firma řeší chybějící detaily ve většině případů operativně a to nemusí dopadnout
dobře.
Obr. 11 IČT snímek na vnitřní ostění okenní výplně
Obr. 12 Snímek viditelného spektra k IČT Obr. 11
1.
ČSN 73 0540-2. Tepelná ochrana budov: Část 2: Požadavky. Praha: Český
normalizační institut, 2011.
2.
DLESEK, Vladislav a Bohuslav STUCHLÝ. Lehké obvodové pláště budov: určeno
posl. stavebního směru vys. škol techn. 1. vyd. Praha: Státní nakladatelství technické
literatury, 1974, 203 s.
3.
LIŠKA, Pavel. Příčiny a důsledky vad typizovaných lehkých obvodových plášťů
budov OD-001 Boletický panel. In: Sborník anotací konference Juniorstav 2013.
Brno: Vysoké učení technické v Brně, Fakulta stavební, 2013, s. 474. ISBN 978-80214-4669-4.
4.
PAŘÍZEK, Vojtěch a František MRLÍK. Lehký fasádní plášť objektů občanské
výstavby. 1. vyd. Praha: Nakladatelství technické literatury, 1972, 103 s.
5.
PETRŮJ, S., K. TUZA a M. VLČEK. Ateliérová tvorba VIII: obvodové pláště budov
- obvodové stěny. 1. vyd. Praha: SNTL - Nakladatelství technické literatury, 1987,
150 s.
6.
SEBESTYÉN, Gyula a Vladislav DLESEK. Lehká prefabrikace. 1. vyd. Praha:
Státní nakladatelství technické literatury, 1979, 339 s., obr. příl.
7.
Stavební fyzika – Area 2010, K-CAD, spol. s r.o.
8.
Fotografie – autorské
Kontaktní údaje
Ing. Pavel Liška
Vysoké učení technické v Brně, Fakulta stavební
Veveří 331/95, 602 00 Brno
Tel: +420 541 148 110
150
IMPLEMENTATION OF HEALTH AND SAFETY DOCUMENTATION
INTO SOFTWARE FOR CONSTRUCTION TECHNOLOGY DESIGN
Lucia Tarábková
Abstract
One way to simplify the method for alerting employees about the risks as well as health and
safety at work is the creation of security software, which would allow, prior to
commencement of the construction process, to inform workers about the potential dangers,
risks, consequences and measures that it for a given activities necessary to perform. The
software should also relie on legislation, as well as responsible people who are associated
with that certain process and risk. In the Czech Republic partially deals with this kind issue
software named CONTEC. However, due to the different legislative requirements as well as
gaps in the system within the section of health and safety, this software is not suitable for
Slovakia. In my contribution I work with this part and I try to fill it with necessary
information, for better practical use and application in practice in Slovakia.
Key words: Health and safety (H&S), construction, Contec
1
NEED OF SUITABLE DOCUMENTATION AND DESIGN OF KEY
DOCUMENTS
Using harmonized documentation that would contain a summary of the key elements relating
to H&S in order to improve and streamline the structure of the H&S management system in
organization can be a helpful tool as well as it may cause the decrease of injuries that could
possibly occur during a construction process. In the next figure I propose the most necessary
documents.
Figure 1 Elements of designing key documents for H&S
151
In figure above a „box“ called H&S Politics represents a document presenting main
principles of organization for ensuring the best conditions for health and safety in a company.
H&S Aims set particular goals to improve health and safety in a company and H&S Program
provides specific suggestions on how to implement those goals. Index of hazards highlights
all the possible hazards which can occur during the realization phase within realization of a
construction, while Preventive action indicates everything that is needed or forbidden in order
to ensure the best safety. Next three documents mostly deal with controlling actions of
management. Trauma plan however provides liable principles in case an accident has already
occurred, so called first aid document. Finally document dealing with necessary Personal
protective equipment (PPE) specifies needed equipment of workers during the realization of
processes.
If there is a prepared documentation for each part of this diagram and if it is followed by all
the employees we can clearly assume it will lead to reduction of occurring injuries. Likewise
if this kind of documentation is similarly or analogically processed for the other two parts of
integrated management system in companies- the quality and the environmental protection, it
would be most likely helpful in means of upgrading the integrated system as a compact unit.
Then it is highly possible we will find some similarities among all three of those units.
However if the next step would link them together we can create an integrated set of
documentation suitable for companies with an integrated management system. This would
cause reduction in a number of required documentation.
Figure 2 Set of documents (examples from Slovakia)
2
REQUIREMENTS FOR PARTICULAR CONSTRUCTION PROCESS
When it comes to realization of a particular construction process, it is always necessary to
prepare suitable set of documents and requirements as well. In the figure below it is shown
what has to be provided in terms of each and every construction process from the preparation
phase until the realization itself.
152
Figure 3 Requirements for particular construction process
Requirements of investors represent trainings of workers, management and if necessary even
all the people who participate on realization of particular construction process. This is made
to ensure an exemplary and safe accomplishment of a process. According to this it is also
necessary to supply workers with relevant legislation. Normally there is an excessive amount
of legislative documents but only part of them concerns with a particular process. Therefore
this part provides only those legislation and documents which are clearly addressed to that
certain process. This should help mainly in better orientation. Next in line is the determination
of hazards when it comes to certain process. It highlights only possible hazards which can
currently occur. Specification of H&S risks in a provided document is a next step. Also all the
needed personal protective equipment (PPE) is summarized in already filled in document
called PPE. Document dealing with preventive action always sums up all the actions that
need to be taken before or even during the realization process of any action concerning that
particular construction process. Even though the trauma plan is every time the same- it does
not change within different processes, it is compulsory for it to be presented during the whole
time. Finally the document for monitoring, which has to be filled after finalization and
sometimes even during the realization of a process itself has to be completed by a responsible
manager or other chief executive.
3
INTEGRATION WITH SOFTWARE CONTEC
Construction- technology software Contec is only provided with basic information such as
those shown in the following figure. When it comes to a specific type of process, software
only points out details about possible risks, people who are being exposed to this risk, causes
on those people and main preventive actions that need to be taken in order to avoid any
accidents. Legislation is also “Czech-oriented” and therefore not so suitable for a Slovak
market.
153
Figure 4 Original window shown in Contec after choosing a specific process
In order to enable better orientation in documents while realization of a particular process I
have upgraded this software with several information based on those needed key documents
mentioned before.
In the figure below there are shown all the filled in facts and references leading to all the
necessary key documents.
154
Figure 5 Upgraded Contec window
However not all of the elements from figure number 1. could have been installed into this
software. Therefore a complete documentation in written form ( Figure no. 3) has to be
available within an organization. Mentioned elements that have been inserted into software
are meant to be helpful mainly for people who have anything to do with a performance of a
certain construction process. It makes it much easier for them to orient themselves not only in
necessary legislation or preventive actions but also in knowledge in helping out when an
accident occurs- First Aid.
4
CONCLUSION
Defects or failures in constructed facilities can result in very large costs. Beyond design
decisions, safety largely depends upon education of workers, vigilance and cooperation
during the construction process and it must be incorporated into education system of each
organization. Workers should be constantly alert to the possibilities of accidents and avoid
taken unnecessary risks.
Health and safety (H&S) management should represent increasingly important concerns for
each company. Even with minor defects, re-construction may be required and facility
operations impaired. In the worst case, failures may cause personal injuries or fatalities. Good
project managers try to ensure that the job is done right the first time.
155
Safety during the construction project is also influenced in large part by decisions made
during the planning and design process.
Sources
1.
GAŠPARÍK, J.: Manažérstvo kvality v stavebnej organizácii. Bratislava: STU v
Bratislave, 2005. ISBN 80-227-2196-4. (in Slovak).
2.
HOWARTH, T.; WATSON, P.: Construction Safety Management, WileyBlackwell, UK 2009. ISBN 978-1-4051-866-5. (in English).
3.
GAŠPARÍK, J.: Effective integrated management system in construction company.
Organization, Technology and Management in Construction: 7th International
conference. Proceedings/ Zadar, Croatia. 2006, ISBN 953-96245-7-6. (in English)
4.
OHSAS 18 001:2009. Systém manažérstva bezpečnosti a ochrany zdravia pri práci.
Požiadavky. (in Slovak).
5.
OHSAS 18 002:2009. Systém manažérstva bezpečnosti a ochrany zdravia pri práci.
Návod na implementáciu. (in Slovak).
Contact
Ing. Lucia Tarábková, PhD.
Slovak university of technology in Bratislava
Faculty of civil engineering
Radlinského 11, 813 68, Bratislava, SR
Tel: +421/ 904 244 105
156
C z e c h S T A V
2 0 1 1
ISBN 978-80-905243-8-5
ETTN 040-13-13022-10-8
vol. IV, 2013
Příspěvky publikované v tomto sborníku vyjadřují názory a stanoviska nezávislých autorů. | Papers published in
this conference proceedings express the viewpoints of their independent authors.
Tato publikace neprošla redakční ani jazykovou úpravou.
INOVACE VE STAVEBNICTVÍ | INNOVATION IN BUILDING CONSTRUCTION

CzechSTAV 2013

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