NUMERICAL PARTICLE MOTION OF RAYLEIGH WAVES IN LATERALLY INHOMOGENEOUS MEDIA

Abstract

Finite difference technique is applied to study Rayleigh wave propagation in laterally inhomogeneous media. The surface Rayleigh wave particle motion trajectory is studied to be a parameter to show the effect caused by lateral inhomogeneity. Computed results show that the trajectory is very sensitive to the presence of lateral inhomogeneity in at least three ways: change of peak amplitude, change of propagation velocity, and inclination of particle motion trajectory. The inclination of particle motion trajectory is particularly sensitive to the presence of lateral velocity variations, and is mainly at the nodes near the discontinuity within half the characteristic wavelength. The models with vertical discontinuity produce more effect on the Rayleigh wave particle motion than the models with inclined discontinuity.