Two-dimensional seismic response analysis of basin effects

Abstract

The site effect of local geological conditions on seismic ground motion is of great importance in earthquake engineering. An analytical method is presented herein to study the basin effect for layered soil systems. The method is based on a coupling of the finite element method and the boundary element method. The near field is modeled by the finite elements whereas the far field is modeled by the boundary element formulation using the multi-layer dynamic fundamental solution that satisfies the radiation condition of waves. In order to validate the analytical approach, a one-dimensional problem is modeled and the results are compared with those of a well-known SHAKE code. Two dimensional seismic response analyses are then performed for various ground systems to study the basin effect. Effects of the ground geometry and material contrast on the seismic responses are discussed in some details.