Scattering of Waves by Inclusions in a Nonhomogeneous Elastic Half Space Solved by Boundary Element Methods

Keywords: Seismic Activity, Soil Properties, Seismic Waves, Earthquake Resistant Design, Wave Scattering, Nonhomogeneous Profiles, and Boundary Element Method.

Abstract: In order to make a structure safe from earthquake damage, a design engineer needs information about the waves to which it will be subjected and the structure's response to them. While a precise prediction of all seismic activity during the life of a structure is virtually impossible, earthquakes do occur within predictable limits with often repeated qualitative characteristics. It is possible to choose a representative earthquake for a given site. However, it must be understood how the excitation is modified by the local conditions at the site. Some of the things influencing wave propagation include soil material properties, layering of the soil, and the behavior of structures embedded in and resting on the soil profile.The present work presents a technique for examining the interaction of soil layers and structures in a two-dimensional profile subjected to incident SH waves. The analysis is carried out in the frequency domain where the response at any frequency in the spectrum is computed by the boundary element method. This enables the efficient solution of complex geometries, including lenses, tunnels, foundations, and cavities. Results are presented which show that the method gives good agreement with known results and that the interaction of closely spaced structures is significant.