Effect of Number of Stories on the Seismic Soil Structure Interaction Performance of Midrise Frame Structures

Abstract

When an earthquakes hits, a state of emergency is declared that shakes lives and infrastructures and provokes aftershocks including fires and medical emergencies. The response of midrise concrete frame structures to a seismic excitation is related to the dynamic interaction between the structure, foundation and soil called soil structure interaction (SSI). To study the effect of structures’ number of stories on the seismic behavior of midrise concrete frame buildings including soil structure interaction effects, 5 to 15 stories structures were simulated by performing 3D time history nonlinear finite element simulations using Abaqus under the influence of El-Centro (1940) and Northridge (1994) earthquakes. The models consisted of frame structures supported by raft foundation and rested on silty sandy soil block. The results presented in terms of story lateral deflection, inter-storey drift, shear force, foundation rocking and response spectrum show that structures’ number of stories significantly affect SSI effects and increasing story number can end in structures’ collapse in some cases.