Analysis Of Framed Structures Considering Site Specific Response Spectrum

Abstract

During an earthquake, surface ground shaking causes severe damage to the structures which depend on the characteristics of subsurface soil. Intensity of ground shaking or peak ground acceleration at different sites can be different during a particular seismic event. The seismic force on a building depends on peak ground acceleration and the time period of the building which is specified In IS 1S93 in terms of zone factor (Z) and spectral acceleration (Sa/g). The objective of the present work is to understand the effect of subsurface soil condition on seismic response of multi storey regular framed structures. Site specific response spectra arc developed for various sites of Ahmedabad using ProSHAKE software. The acceleration time history, recorded at Passport office building of Ahmedabad on 26" January 2001 Bhuj earthquake. is considered as input motion for different sites to j : acceleration time history of ground as well as response spectra. Rigid jointed frame structures with 3 to 20 storeys on different soil sites of Ahmed a bad are considered. Comparison of the results in terms of internai forces in ground floor columns is carried out considering site specific response spectrum and standard response spectrum of ISlS9.V2002.Tlte present study highlights the importance of site specific response analysis of buildings and will be more relevant during seismic micro-7onation of major cities.