Effect of foundation embedment on the response of a multi-story building to earthquake excitation

During an earthquake, the behaviour of any structure is affected not only by the superstructure response, but also by the response of the soil beneath. Recent structural failure patterns have indicated the significance of soil-structure interaction (SSI) effects. The present study focuses on SSI analysis considering the embedment depth of the foundation of a symmetric six stories reinforced concrete (RC) space bare frame building resting on stiff soil and subjected to seismic loading. The finite element analysis software ANSYS v17.2 is used. Time history (TH) analysis has been adopted. The Response in terms of lateral displacements, base shear forces, base moments and variation in natural time periods are calculated from the analysis of the soil foundation structure interaction (SFSI) model. Results are compared with that obtained from conventional method assuming rigid support at the base (fixed base) of the structure. The results show that the SFSI considering different embedment depths are significant in altering the seismic response of the multi-story building (MSB).