Hits: 4802
During extensive field surveys in the state of Uttarakhand (India) the most prevalent configurations of buildings on slopes have been identified, which can be broadly identified as step-back, and step- and set-back configurations. In addition, for buildings on steep rock slopes, foundations resting at two different levels can often be observed. The present study focuses on the seismic fragility analysis of step-back hill buildings, which is the most commonly found configuration in the Indian Himalayas. The Incremental Dynamic Analysis procedure is used for obtaining dynamic capacity curves, which are used for fragility analysis. A set of 30 ground motion time histories has been selected and scaled using the intensity measure Sa (T1, 5%). It is observed that the hill buildings designed as per the existing code provisions for buildings on flat topography exhibit a very high probability of incipient collapse for the DBE and MCE levels of seismic demand. The performance can be significantly improved by making minor changes in the structural configuration.