Amplification of waves by an orthotropic basin: Sagittal plane motion

Scattering of elastic waves by an orthotropic basin of arbitrary shape embe dded in a half-space is investigated for the sagittal plane motion using an indirect boundary integral equation approach. Steady-state results were ob tained for incident plane harmonic pseudo P-, S-, and Rayleigh waves. Detai led convergence analysis of the method is presented. Green's functions are evaluated by using adaptive Newton-Cotes or Filon quadratures. Surface grou nd motion is presented for semicircular and semielliptical basins with diff erent material properties and various angles of incidence. The results show that surface motion strongly depends upon nature of incident wave, geometr y and material properties of the basin, acid location of the observation po int. Comparison with isotropic basin response demonstrates that anisotropy is very important in amplification of surface ground motion. Copyright (C) 1999 John Wiley & Sons, Ltd.