Interaction analysis of space frame-shear wall-soil system to investigate forces in the columns under seismic loading

Abstract

The phenomenon of soil-structure interaction greatly affects the design of RC shear wall building frame resting on a deformable soil. In the present work, a G + 5 RC shear wall building frame (4 × 3 bays and 6 storeys) having open foundation (isolated footings) and resting on deformable soil is considered, to investigate axial force and bending moments in the columns. The 3-D interaction analysis is carried out using finite element software ANSYS. The superstructure and soil are considered to follow linear stress-strain relationship. The interaction analysis is carried out under various combinations of seismic loading as per IS-1893 (Part I): 2002. It is found that interaction phenomenon causes significant redistribution of forces in the superstructure. The governing bending moments in the bottom columns, along the direction of seismic loads, are increased many times as a result of soil-structure interaction as compared to the conventional non-interaction analysis.