Performance assessment and strengthening proposal of an existing building

Kao odgovor na pojavu snažnih potresa u seizmičkim se propisima provode revizije metoda za projektiranje građevina otpornih na seizmička djelovanja. Poznato je da su mnoge postojeće građevine smještene u seizmički aktivnim područjima diljem svijeta. Potresi uzrokuju znatna oštećenosti elemenata konstrukcije, te djelomično ili potpuno rušenje građevina. Zbog toga se, u okviru različitih seizmičkih propisa, diljem svijeta provodi ocjenjivanje seizmičkog ponašanja i postupaka pojačanja postojećih građevina. Zahvaljujući razvoju računalne tehnologije, nelinearne metode danas nude sve pouzdanije postupke za određivanje ponašanja građevina. U ovom se radu najprije provodi nelinearna analiza ponašanja postojeće tipične armiranobetonske građevine srednje visine prema turskom seizmičkom propisu – 2018 te prema američkoj normi ASCE. Nakon ocjene oštećenosti konstrukcijskih elementa, građevina je pojačana čeličnim razuporama te je zatim analiza ponovljena. U postupku je korišten računalni program za analizu konačnih elemenata SAP2000. Koeficijenti oštećenosti konstrukcijskih elemenata te modalna svojstva i međukatni pomaci, određeni su i uspoređeni prema oba spomenuta propisa, te je zaključeno da predložena metoda pojačanja može biti prihvatljivo alternativno rješenje za takve građevine.Due to major-scale earthquakes, revisions of earthquake resistant structural design methods have periodically been made in seismic codes. It is known that many existing buildings are located in active seismic zones in all parts of the world. Severe damage to structural members, with partial or total collapse of buildings, has been observed in past earthquakes. Consequently, the evaluation of seismic performance and strengthening techniques of the existing buildings according to various seismic codes has become a global issue in structural engineering. With the development of computer technology, non-linear methods have been offering increasingly reliable evaluation procedures in the performance-based assessment of buildings. In this study, non-linear performance analysis of an existing typical mid-rise reinforced concrete building is first performed according to Turkish Building Earthquake Code-2018 and American Standard, ASCE. After evaluation of damage to structural members, the building is strengthened by steel braces and the analysis is performed once again. The SAP2000 finite elements analysis software is utilized in the solutions. Damage ratios of structural members as well as modal properties and storey drift ratios are determined and compared according to both codes, and it is concluded that the proposed strengthening method could be a significant alternative in such buildings