Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
Risk - based seismic design of buildings - An example of an eight storey reinforced concrete building |
Sekundarni povzetek: |
Experiences from recent earthquakes around the world show that the risk of life and property loss due to seismic hazard is too high if buildings are not properly designed. This finding is not new, since there are many different standards for the design of structures in seismic areas. Those standards were developed to reduce seismic risk, but they only prescribe the capacity design procedure for a given design earthquake. Therefore we cannot claim that the current standards for seismic resistant design of structures control seismic risk to such an extent that would be acceptable for all types of structures and for all investors. In order to overcome this shortcoming we developed a procedure for design of buildings based on seismic safety, which is defined with acceptable seismic risk. The process is iterative and requires the use of nonlinear methods of analysis. Firstly, the structure should be preliminarily designed, which can be achieved by utilising standards for seismic resistant design of buildings. Then we estimate the seismic risk and compare it to an acceptable or tolerated risk. If the seismic risk is too high, we take measures to reduce it and re-evaluate it for a new and improved structure. The proposed procedure was demonstrated by means of an example of an eight-storey reinforced concrete building. For the base structure that was designed under current standards, we found, that the risk of collapse due to earthquakes was too high. We also proved that the capacity design method does not provide the assumed collapse mechanism, which is a weakness of current standards for seismic resistant design. Finally, we showed that the adequate seismic safety can be provided by a small increase of the columns' reinforcement, which does not substantially affect the cost of the investment, but reduces the seismic risk by a factor of two. |
Sekundarne ključne besede: |
graduation thesis;earthquake engineering;reliability of structures;seizmic risk;reinforced concrete frame;pushover analysis;limit state;seizmic hazard; |
Vrsta datoteke: |
application/pdf |
Vrsta dela (COBISS): |
Diplomsko delo |
Komentar na gradivo: |
Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo |
Strani: |
XIV, 118 str. |
Vrsta dela (ePrints): |
thesis |
Naslov (ePrints): |
Risk - based seismic design of buildings - An example of an eight storey reinforced concrete building |
Ključne besede (ePrints): |
potresno inženirstvo;zanesljivost konstrukcij;potresno tveganje;projektiranje konstrukcij;armiranobetonski okvir;nelinearna statična analiza;mejno stanje;potresna nevarnost |
Ključne besede (ePrints, sekundarni jezik): |
earthquake engineering;reliability of structures;seismic risk;reinforced concrete frame;pushover analysis;limit state;seismic hazard |
Povzetek (ePrints): |
Izkušnje iz nedavnih potresov po svetu kažejo, da je tveganje za izgubo življenja in premoženja zaradi potresne nevarnosti previsoko, če stavbe niso primerno projektirane. To spoznanje ni novo, saj za projektiranje konstrukcij na potresnih območjih obstaja veliko različnih standardov. Razviti so bili z namenom, da bi omejili potresno tveganje, kar je v standardih posredno upoštevano s predpisanim načrtovanjem nosilnosti za izbran projektni potres. Zato ne moremo trditi, da trenutno veljavni standardi za potresnoodporno projektiranje konstrukcij kontrolirajo potresno tveganje do te mere, da bi bilo sprejemljivo za vse vrste konstrukcij in vse investitorje. Z namenom, da bi to pomanjkljivost odpravili, smo v okviru diplomske naloge razvili postopek za potresnovarno projektiranje stavb, pri čemer varnost definiramo s sprejemljivim potresnim tveganjem. Postopek je iterativen in zahteva uporabo nelinearnih metod analize. Izhajamo iz osnovne konstrukcije, ki jo lahko določimo z uporabo standardov. Za to konstrukcijo ocenimo potresno tveganje in ga primerjamo s sprejemljivim oz. toleriranim tveganjem. V primeru, da je potresno tveganje preveliko, sprejmemo ukrepe za njegovo zmanjšanje in ga ponovno ocenimo za novo izboljšano konstrukcijo. Uporabo postopka smo prikazali na primeru osem-etažne armiranobetonske stavbe. Za osnovno konstrukcijo, ki je bila projektirana po trenutno veljavnih standardih, smo ugotovili, da je tveganje za porušitev zaradi potresov preveliko. Izkazalo se je tudi, da je mehanizem porušitve preučevane konstrukcije različen od tistega, ki je predpostavljen z metodo načrtovanja nosilnosti. To kaže na pomanjkljivost trenutno veljavnih standardov za potresnoodporno projektiranje. Zadostno varnost smo nato dosegli z manjšim povečanjem armature v stebrih, kar nima bistvenega vpliva na vrednost investicije, vendar zmanjša tveganje za faktor dva. |
Povzetek (ePrints, sekundarni jezik): |
Experiences from recent earthquakes around the world show that the risk of life and property loss due to seismic hazard is too high if buildings are not properly designed. This finding is not new, since there are many different standards for the design of structures in seismic areas. Those standards were developed to reduce seismic risk, but they only prescribe the capacity design procedure for a given design earthquake. Therefore we cannot claim that the current standards for seismic resistant design of structures control seismic risk to such an extent that would be acceptable for all types of structures and for all investors. In order to overcome this shortcoming we developed a procedure for design of buildings based on seismic safety, which is defined with acceptable seismic risk. The process is iterative and requires the use of nonlinear methods of analysis. Firstly, the structure should be preliminarily designed, which can be achieved by utilising standards for seismic resistant design of buildings. Then we estimate the seismic risk and compare it to an acceptable or tolerated risk. If the seismic risk is too high, we take measures to reduce it and re-evaluate it for a new and improved structure. The proposed procedure was demonstrated by means of an example of an eight-storey reinforced concrete building. For the base structure that was designed under current standards, we found, that the risk of collapse due to earthquakes was too high. We also proved that the capacity design method does not provide the assumed collapse mechanism, which is a weakness of current standards for seismic resistant design. Finally, we showed that the adequate seismic safety can be provided by a small increase of the columns' reinforcement, which does not substantially affect the cost of the investment, but reduces the seismic risk by a factor of two. |
Ključne besede (ePrints, sekundarni jezik): |
earthquake engineering;reliability of structures;seismic risk;reinforced concrete frame;pushover analysis;limit state;seismic hazard |
ID: |
8312138 |