Analysis of Surface Waves in an Elastic Medium with a Porous Saturated Layer

Resumo

We study the propagation of seismoacoustic waves in a three-layered medium consisting of a uniform isotropic deformable solid layer that is loaded with a uniform porous layer saturated with fluid. In turn, the porous layer covers a homogeneous isotropic solid half-space. This medium models the geological section in which the upper ground layer is separated from the deep rocks by a porous layer containing a significant amount of fluid. The obtained dispersion relation is analyzed and its solutions for the practically important cases are presented. The effects due to the liquid-phase motion with respect to the relatively deformable solid skeleton during the wave propagation are pointed out. The features of the dispersion curves and the spatial distribution of the mode fields, which allow one not only to determine the presence of a fluid-saturated porous layer under the upper ground layer, but also estimate the thickness and occurrence depth of the porous layer, are revealed.