Effects of Soil-Foundation-Bridge Interaction Subjected to Spatially Varying Earthquake Ground Motion

Abstract

The primary purpose of this study is to investigate stochastic responses of a cable-stayed bridge which is built on the Mississippi River in 1987 in USA, subjected to the spatially varying earthquake ground motion by using the finite element method taking account of soil-structure interaction (SSI) effects. The bridge is modelled as a two- dimensional to determine the stochastic response of the bridge. Spatially varying earthquake ground motions is considered in the analysis. Depending upon the earthquake motion, the response values of the bridge founded on firm, medium and soft soil strata are obtained, separately. The effects of soil–structure interaction on the stochastic response of the cable-stayed bridge are investigated including foundation as a vertical pile groups. The soil–pile interaction is linearly idealized as an upright beam on the Winkler foundation model. Results indicate that taking into account soil-structure interaction could increase element forces and displacement of bridge along the deck and height of tower especially in case of soft foundation soil strata.