Vpliv stopnjevanja sprejemljivega potresnega tveganja na armiranobetonsko okvirno konstrukcijo

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Podatki

Jezik:	Slovenski jezik
Leto izida:	2013
Izvor:	Ljubljana
Tipologija:	2.09 - Magistrsko delo
Organizacija:	UL FGG - Fakulteta za gradbeništvo in geodezijo
Založnik:	[D. Podgorelec]
UDK:	624.042.7:624.012.45(043.3)
COBISS:	6412129
Št. ogledov:	1924
Št. prenosov:	604
Ocena:	0 (0 glasov)
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Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	ǂThe ǂimpact of the escalation of acceptable seismic risk on reinforced concreteframe structure
Sekundarni povzetek:	Eurocode 8 prescribes that structures are sufficiently designed if they are capable to withstand a design seismic action, which is defined for a given earthquake recurrence interval associated with ultimate and serviceability limit state. The first requirement is fulfilled if it is proven that the structure does not collapse for a seismic action associated with return period of 475 years. A shortcoming of such design procedure is that the decision is based on conditional probability of failure. In reality, “stronger” or even “weaker” earthquake can cause collapse of the building. This shortcoming of the existing standards for seismic resistant design of buildings can be overcome by introducing more scientifically-oriented design procedures, which is the main objective of the research thesis. The new design procedure used in this research is based on target reliability that is expressed by the acceptable annual probability of collapse of structure. As a case study, an eight-storey reinforced concrete frame building was designed taking into account different level of acceptable seismic risk in order to investigate the relationship between the escalation of target reliability and the global parameters of the structure. We found that the escalation of acceptable risk by a factor of 50 resulted in an increase of the total design seismic forces by about a factor of 10. This was reflected in the quantity of materials used. The amount of reinforcement was increased by about 4.6 times, while the volume of the concrete was greater by a factor of 1.9. It appeared that the structural system is not suitable if the criterion of acceptable risk is very strict. Based on the results of the study it can be concluded that the proposed force-based design procedure to target reliability is quite similar to that prescribed by Eurocode 8, as it essentially differs only in the definition of the seismic action, which, according to the new procedure, depends on the target reliability rather than earthquake recurrence interval.
Sekundarne ključne besede:	civil engineering;master of science thesis;seismic risk;seismic hazard;seismic design for earthquake safety;pushover analysis;reliability-based seismic action;N2 method;reinforced concrete frame;
Vrsta datoteke:	application/pdf
Vrsta dela (COBISS):	Magistrsko delo/naloga
Komentar na gradivo:	Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo
Strani:	XVI, 101 str.
Vrsta dela (ePrints):	thesis
Naslov (ePrints):	The impact of the escalation of acceptable seismic risk on reinforced concrete frame structure
Ključne besede (ePrints):	potresno tveganje;potresna nevarnost;potresnoodporno projektiranje;nelinearna statična (potisna) analiza;zanesljivost konstrukcij;N2 metoda;armiranobetonski okvir
Ključne besede (ePrints, sekundarni jezik):	seismic risk;seismic hazard;design for earthquake safety;pushover analysis;reliability-based seismic action;N2 method;reinforced concrete frame
Povzetek (ePrints):	V skladu s trenutno veljavnim standardom za potresnoodporno projektiranje (Evrokod 8) mora biti konstrukcija projektirana tako, da sta izpolnjeni temeljni zahtevi po neporušitvi in omejitvi poškodb. Prvi zahtevi zadostimo, če dokažemo, da se konstrukcija ne poruši pri potresu s povratno dobo 475 let. Takšen postopek projektiranja je pomanjkljiv, saj temelji na pogojni verjetnosti porušitve. Dejstvo je, da se lahko pojavijo »močnejši« ali celo »šibkejši« potresi, ki bodo povzročili porušitev objekta. To pomanjkljivost obstoječih standardov za projektiranje objektov je mogoče odpraviti z uvedbo znanstveno bolj utemeljenega postopka projektiranja, kar je tudi glavni cilj magistrskega dela. Postopek projektiranja, ki ga uporabimo v nalogi, temelji na zagotavljanju ciljnega potresnega tveganja, ki ga izrazimo z letno sprejemljivo verjetnostjo porušitve objekta. Obravnavamo osem-etažno okvirno konstrukcijo, ki jo projektiramo na različne stopnje potresnega tveganja, da bi ugotovili relacijo med ciljno zanesljivostjo in globalnimi parametri. Ugotovili smo, da stopnjevanje sprejemljivega tveganja za faktor 50 povzroči povečanje celotne projektne potresne sile približno za faktor 10. To se odraža v količini porabljenega materiala. Količina armature se poveča približno za 4,6-krat, medtem ko je količina betona večja za faktor 1,9. Izkaže se tudi, da okvirni konstrukcijski sistem ni primeren, če je kriterij sprejemljivega tveganja prestrog. Na osnovi rezultatov študije lahko zaključimo, da je predlagan postopek projektiranja na ciljno zanesljivost precej podoben postopku projektiranja po standardu Evrokod 8, saj se bistveno razlikuje le v definiciji potresne obtežbe, ki je po novem postopku odvisna od ciljne zanesljivosti.
Povzetek (ePrints, sekundarni jezik):	Eurocode 8 prescribes that structures are sufficiently designed if they are capable to withstand a design seismic action, which is defined for a given earthquake recurrence interval associated with ultimate and serviceability limit state. The first requirement is fulfilled if it is proven that the structure does not collapse for a seismic action associated with return period of 475 years. A shortcoming of such design procedure is that the decision is based on conditional probability of failure. In reality, “stronger” or even “weaker” earthquake can cause collapse of the building. This shortcoming of the existing standards for seismic resistant design of buildings can be overcome by introducing more scientifically-oriented design procedures, which is the main objective of the research thesis. The new design procedure used in this research is based on target reliability that is expressed by the acceptable annual probability of collapse of structure. As a case study, an eight-storey reinforced concrete frame building was designed taking into account different level of acceptable seismic risk in order to investigate the relationship between the escalation of target reliability and the global parameters of the structure. We found that the escalation of acceptable risk by a factor of 50 resulted in an increase of the total design seismic forces by about a factor of 10. This was reflected in the quantity of materials used. The amount of reinforcement was increased by about 4.6 times, while the volume of the concrete was greater by a factor of 1.9. It appeared that the structural system is not suitable if the criterion of acceptable risk is very strict. Based on the results of the study it can be concluded that the proposed force-based design procedure to target reliability is quite similar to that prescribed by Eurocode 8, as it essentially differs only in the definition of the seismic action, which, according to the new procedure, depends on the target reliability rather than earthquake recurrence interval.
Ključne besede (ePrints, sekundarni jezik):	seismic risk;seismic hazard;design for earthquake safety;pushover analysis;reliability-based seismic action;N2 method;reinforced concrete frame
ID:	8312853