Dynamic Behavior of Code-Designed Existing Buildings with Non-Ductile Detailing in Pakistan

Abstract

Pakistan is a developing country with a extensive range of design and construction practices, which needs to evolve its own strategies for seismic hazard evaluation. The last two decade have pointed our shortcoming in design procedures of structures, specifically in resisting lateral forces. The October 2005 earthquake was one of the most catastrophic earthquakes in the history of the country causing immense loss of life and property. After this loss attention is now being given to the evaluation of the adequacy of strength in structures to resist strong ground motions. After 2005 earthquake Pakistan Building Code 1986 was revised and published in the year 2007. The main reason for the loss of life and property was inadequacy of knowledge of behavior of structures during ground motions. The vulnerability of the structures against seismic activity must be essentially studied. Usual design Practice in Pakistan is to design buildings according to UBC-97/ BCP-07, which is based on Equivalent lateral force procedure and Response Spectrum Analysis. Linear Dynamic Analysis of buildings is very necessary for the true dynamic behavior of building as it utilizes actual ground motions record and consider the effects of higher modes. Finite element model of Six existing buildings was generated in ETABS and analyzed by Equivalent Lateral Force procedure, Response Spectrum Analysis and Linear Time History Analysis for same seismic parameters. Seismic responses i.e. Story Displacements, inter story Drifts Ratios, story shares and story moments from ELF and RSA were then compared with benchmark LTHA.