Time Period Estimation of RC Frame Buildings Through Soil Stiffness Modeling

Abstract

Interaction between a structure and its supporting soil, if it is soft, is of great importance in the design of safer structures and its foundations subjected to earthquake motions. Generally, the structures are analysed considering the foundation ground as stiff and the structures experiencing free field motion. The stiffness modeling of stiff, medium and soft or flexible soil types has been done based on shear wave velocities. In this work, base shear and displacement of a multi-storeyed building on flexible soil considering the effects of soil stiffness are presented in terms of its time period. RC framed buildings with different fundamental time periods and with different foundation soil stiffnesses have been analysed to get a relationship between the time periods. It is expected that the relations presented between time periods and responses would be helpful in design of buildings on soft soil.