SEISMIC VULNERABILITY OF BUILDINGS IN HILLY AREAS

Abstract

Buildings on hill slopes have considerably different structural configurations than those on level land. The most popular layouts of structures on slopes have been commonly taken as step-back, step-and set-back designs, and sometimes for steep slopes, foundations sitting on two separate levels have been recorded during extensive field studies in the Indian Himalayan regions. The study in this paper focuses on the comparison of split foundation hill building and step-back hill buildings by response spectrum analysis, time history analysis, and fragility analysis (using Pushover Analysis). In this zone IV with rock and hard soil is considered for analysis. In this study both the configurations are subjected to acceleration time data of earthquake at Uttarkashi in Oct 1991 (Mw=6.8, PGA=0.31g) and the analysis results of split foundation building and step back building are compared. It is observed that the step back building is more suitable in hilly areas as compared to split foundation designed building as step back building gives less displacement, less drift, less shear etc.