This paper presents the effect of earthquake motions on the response of a three-dimensional ten storey reinforced concrete structure with and without considering soil-structure interaction (SSI). The RC building asymmetric in plan and total height 30m, located in seismic zone III is considered. Push-over analysis is carried out by incorporating user defined hinge properties in X-direction and Y-direction of the frame. The four different cases studied are, (1) Fixed base without considering soil structure interaction, (2) Flexible base by considering hard soil, (2) Flexible base by considering medium soil, (4) Flexible base by considering soft soil. It was found that soil-structure interaction can affect the seismic performance of the building in terms of seismic force demands and deformations. From the capacity curve it is observed that SSI effects are significant for soft soil conditions and negligible for structures situated on hard soil conditions.

Keywords: Push-over analysis, Seismic capacity, Soil structure interaction, Flexible base.