Surface Rayleigh-Lamb waves in stratified substrate

Abstract

Propagation of Rayleigh - Lamb waves has shortage of theoretical studies and demands in deeper analyses. Understanding the process of propagation of Rayleigh-Lamb waves depending on the geometrical and acoustical properties of the individual layers within the Earth’s crust is of great importance for the NDT of Earth exploration and development of seismic protection of buildings and structures. Propagation of these waves in the Earth’s crust upper layers is studied by analytical methods. A mathematical model for analyzing Rayleigh -Lamb waves propagating in stratified media is worked out. The analytical solution is constructed using Cauchy complex formalism and the method called Modified Transfer Matrix (MTM). As an example a multilayer system modeling the Earth’s crust, consisting of sedimentary rocks, a layer of granite, basalt and mantle, is considered. Equation for dispersion relations is derived. Fundamental modes of the dispersion curves for a stratified media are obtained.