SCATTERING OF ANTIPLANE WAVES BY INHOMOGENEOUS ALLUVIAL VALLEYS

Scattering problems of antiplane waves incident upon inhomogeneous alluvial valleys are studied by using the integral equation methods. Three types of integral equation approaches are presented and compared each other. The first one is the boundary-domain integral equation based on the static fundamental solution for a homogeneous body. The second one is identical to the first one, except that the dynamic fundamental solution is employed. The last one is the boundary integral equation for the scatterer with ad hoc inhomogeneity, for which the fundamental solution is obtained. The numerical results show that the soft surface layer in alluvial valleys induces the large amplification and long duration of surface motions, which reflects the important problem in earthquake engineering.