Potresna analiza šest-etažne nesimetrične stavbe

Abstract

Keywords

Data

Language:	Slovenian
Year of publishing:	2009
Source:	Ljubljana
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FGG - Faculty of Civil and Geodetic Engineering
Publisher:	[M. Kosič]
UDC:	006(4):624.012.45:624.042.7(043.2)
COBISS:	4794977
Views:	1864
Downloads:	579
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Seismic analysis of the six-storey asymmetric building
Secondary abstract:	The present work deals with the seismic analysis and design of six-storey building according to standard Eurocode 8. Although the building can be conceptually classified as wall- equivalent dual system, it did not satisfy the criteria of minimal torsional rigidity. As a result the building was designed as torsionally flexible system. Modal response spectrum analyses was performed with the program ETABS. As a result of some assumptions different structural models were used for determination of seismic design forces. In addition the influence of modeling of walls with beam-column or shell elements was also studied. Particular attention was dedicated to the influence of effective slab widths in the design process of primary seismic beams. In the second part of the thesis, the selected part of the building was designed taking in account the ultimate limit and serviceable limit state. Considering the small number of stories, the structure was designed for medium class of ductility. The comparison between results of different models indicates that systems where walls are modeled with beam-column elements are in general more flexible. Therefore in this system the load on frames is larger and consequently action on walls is reduced. However, the results of both models are similar since the use of one or another model practically leads to the same results. The influence of effective slab width of beams increases the overall stiffness of beams. Therefore the internal forces in frames are significantly increased, but the internal forces in walls are practically the same. Consequently, the assumption of the effective slab width in the seismic analysis in general leads to safer design of structure. Since the flexural and shear reinforcement in the walls is high it is clear that the internal forces due to seismic action in walls are high. First solution to this problem would be applying redistribution of seismic action to other walls. Second solution would be to select the ductility class high in the design process of building. Lastly, the alternative would be modifying the conceptual design of the building by adding new walls. This solution is usually not in favor but would results in significantly increased seismic safety of the building.
Secondary keywords:	graduation thesis;concrete building;torsionally flexible system;effective slab width;modeling of walls with beam-column of shell elements;design of concrete buildings according to Eurocode 8;
File type:	application/pdf
Type (COBISS):	Undergraduate thesis
Thesis comment:	Univ. Ljubljana, Fak. za gradbeništvo in geodezijo
Pages:	XXI, 156 str., pril.
Type (ePrints):	thesis
Title (ePrints):	Seismic analysis of the six-storey asymmetric building
Keywords (ePrints):	armiranobetonska stavba;torzijsko podajen sistem;sodelujoče širine plošč;modeliranje sten z linijskimi ali ploskovnimi elementi;projektiranje betonskih stavb po Evrokodu 8
Keywords (ePrints, secondary language):	concrete building;torsionally flexible system;effective slab width;modeling of walls with beam-column or shell elements;design of concrete buildings according to Eurocode 8
Abstract (ePrints):	Diplomska naloga obravnava potresno analizo šest-etažne stavbe v skladu s standardom za projektiranje potresnoodpornih konstrukcij Evrokod 8. Po zasnovi je stavba mešan sistem ekvivalenten stenastemu, vendar ne izpolnjuje zahtev glede minimalne torzijske togosti. Obravnavana stavba se tako uvršča med torzijsko podajne objekte. Modalna analiza stavbe je bila izvedena s pomočjo programa ETABS 9.0. Odziv stavbe je bil določen z uporabo različnih matematičnih modelov in ob upoštevanju različnih predpostavk. Preučen je bil vpliv modeliranja sten z linijskimi ali ploskovnimi modeli ter vpliv sodelujočih širin plošč pri modeliranju togosti primarnih potresnih gred. Drugi del diplomske naloge obravnava dimenzioniranje izbranih elementov stavbe na podlagi rezultatov potresne analize. Glede na to, da ima stavba razmeroma malo etaž je bila projektirana za srednjo stopnjo duktilnosti. Iz primerjave rezultatov linijskega in ploskovnega modela smo ugotovili, da so mešani sistemi modelirani izključno z linijskimi elementi bolj podajni. Pri takšnih modelih so obremenitve okvirov večje, stene pa so manj obremenjene. V okviru inženirske natančnosti so razlike v obremenitvah zanemarljive, tako da uporaba enega ali drugega modela privede do podobnih rezultatov. Upoštevanje sodelujočih širin plošč pri modeliranju togosti primarnih potresnih gred poveča obremenitve okvirov in rahlo razbremeni stene. Razbremenitev sten je zanemarljiva,povečanje obremenitev okvirov pa precejšnje. Z modeliranjem sodelujočih širin smo pri projektiranju okvirov v splošnem na varni strani. Iz rezultatov dimenzioniranja je razvidno, da so stene najbolj obremenjeni elementi stavbe, saj so armirane s precejšno količino vzdolžne in strižne armature. Obremenitev najbolj obremenjene stene bi lahko deloma zmanjšali s prerazporeditvijo obremenitev na sosednje stene. Druga možnost bi bila projektiranje stavbe za visoko stopnjo duktilnosti. Skrajna možnost, ki bi bila s stališča potresne varnosti najboljša, pa bi bila sprememba zasnove stavbe z dodajanjem novih sten.
Abstract (ePrints, secondary language):	The present work deals with the seismic analysis and design of six-storey building according to standard Eurocode 8. Although the building can be conceptually classified as wall- equivalent dual system, it did not satisfy the criteria of minimal torsional rigidity. As a result the building was designed as torsionally flexible system. Modal response spectrum analyses was performed with the program ETABS. As a result of some assumptions different structural models were used for determination of seismic design forces. In addition the influence of modeling of walls with beam-column or shell elements was also studied. Particular attention was dedicated to the influence of effective slab widths in the design process of primary seismic beams. In the second part of the thesis, the selected part of the building was designed taking in account the ultimate limit and serviceable limit state. Considering the small number of stories, the structure was designed for medium class of ductility. The comparison between results of different models indicates that systems where walls are modeled with beam-column elements are in general more flexible. Therefore in this system the load on frames is larger and consequently action on walls is reduced. However, the results of both models are similar since the use of one or another model practically leads to the same results. The influence of effective slab width of beams increases the overall stiffness of beams. Therefore the internal forces in frames are significantly increased, but the internal forces in walls are practically the same. Consequently, the assumption of the effective slab width in the seismic analysis in general leads to safer design of structure. Since the flexural and shear reinforcement in the walls is high it is clear that the internal forces due to seismic action in walls are high. First solution to this problem would be applying redistribution of seismic action to other walls. Second solution would be to select the ductility class high in the design process of building. Lastly, the alternative would be modifying the conceptual design of the building by adding new walls. This solution is usually not in favor but would results in significantly increased seismic safety of the building.
Keywords (ePrints, secondary language):	concrete building;torsionally flexible system;effective slab width;modeling of walls with beam-column or shell elements;design of concrete buildings according to Eurocode 8
ID:	8310513