Numerical Investigations on Seismic Response of Structures under the Effect of Infinite Boundary of Soil-Structure Interaction

Abstract

The damage caused by large earthquakes is not only due to structures but also due to the soil failure, where the dynamic response varies considerably from the fixed base state because of the interaction between the ground and the structure. The main objective of this paper is to study the effect of the infinitely extended soil on the dynamic response of the structure. A three-dimensional dynamic analysis of reinforced concrete buildingconsidering the effect of soil-structure interaction is performed. Building with a different number of stories rest on soil with various characteristics have been taken into consideration. For simulation of wave propagation due to far-field effects, coupled finite-infinite elements is presented for modeling the soil. The infinite boundary provides a powerful tool for dealing with wave propagation problems. The analysis is performed through a finite element method which is implemented in ABAQUS program. An earthquake load is applied in the horizontal direction with various boundary conditions such as; free, and infinite boundary. The effect of boundary on the dynamic response of structure are investigated. The significant difference in dynamic response is observed when infinite boundaries are used, especially in the case of soft soil, where the existence of infinite elements leads to absorption of energy and thus greatly reduce the lateral displacement of the structure.