Scattering of Plane Waves by Cylindrical Cavity in Unsaturated Poroelastic Medium

The scattering of elastic waves by underground cavities is an active research topic for its broad applications in various fields, such as earthquake engineering, the blast resistance of underground structures, geophysical exploration, etc. In most previous studies, the sounding medium was treated as an ideal elastic medium or a saturated poroelastic medium. The understanding of the scattering of elastic waves by cavities in unsaturated porous media is limited. In this study, the scattering of plane P1 waves and SV waves by a cavity with a permeable surface in an infinite unsaturated porous medium is solved by the wave function expansion method. The dynamic stress concentration at the cavity surface is investigated by taking P1 wave incidence, for example. Numerical results illustrate that the scattering of plane waves around the cavity strongly depends on the frequency of the incident waves, and the saturation, Poisson’s ratio, and porosity of the surrounding medium.