Multi-hazard performance evaluation of hillside buildings under earthquake and landslide

Abstract

Earthquake-induced landslide, a cascading hazard in the hilly region, can substantially increase the damaging effects of an earthquake. This necessitates the performance evaluation of the buildings situated in the hilly region under landslide-only and landslide following earthquake. The present study assesses the performance of two commonly observed hillside building configurations, i.e., step-back and split foundation, subjected to the above-mentioned multi-hazard scenarios using an uncoupled approach. The uncertainty in the soil properties, which influence the landslide-induced forces, is considered based on laboratory tests of the soil samples collected from active-landslide sites and the existing database of landslide events. Three-dimensional hillside buildings are analysed for uphill-side landslide scenarios by performing force-controlled nonlinear static analyses. Further, a suite of earthquake ground motions is scaled to a predefined intensity level and nonlinear time history analyses are then performed to obtain the damaged state of the buildings prior to assessing the landslide response. It is observed that the earthquake loading history and its direction of excitation significantly affect the response of hillside buildings under landslide following earthquake. Further, it is also observed that the step-back building is more vulnerable to landslide damage as compared to its split foundation counterpart for a given uphill-side landslide scenario.