A Hybrid Approach for Scattering of Elastic Waves by Three-Dimensional Irregularities of Arbitrary Shape.

Abstract

A hybrid technique is developed for studying scattering of elastic waves by non-axisymmetric three-dimensional near-surface inhomogeneities. The technique combines an indirect boundary integral equation method with the finite element approach. Special emphasis is placed on inhomogeneities in the form of dipping layers embedded in a half-space and subjected to plane incident P, SV, SH, and Rayleigh waves.The accuracy and efficiency of the hybrid technique are examined through several numerical examples. The comparisons with the results obtained by a boundary integral equation method validate the accuracy of the hybrid technique. The versatility of the method is demonstrated by considering several types of inhomogeneous basins containing multiple horizontal and dipping layers. It is found that the numerical efficiency of the hybrid technique becomes much higher than that of the boundary integral equation methods as the structure of the inhomogeneities gets more complex.