Abstract
Buildings are susceptible to soil structure interaction effects due to the induced changes in the dynamic characteristics of soil during seismic excitation. Because of this detrimental effect, this paper aims at clarifying the soil structure interaction effect on the seismic response of buildings under strong ground motions to provide damage control and enhance the safety level of such buildings. An iterative dynamic analysis was performed using the SAP2000 program to carry out three dimensional time history analysis of nonlinear soil-foundation-building models under a great earthquake ground motion, and the results show that incorporating the soil structure interaction could have a detrimental effect on the building performance and overestimates the top displacements response. On the contrary flexible bases of buildings have a noticeable effect on the structural behavior of buildings by providing pronounced reduction in the internal forces of superstructure response compared to the fixed base buildings.