Wave propagation in layered dry, saturated and unsaturated poroelastic media

An exact stiffness formalism is presented to study harmonic and transient wave propagation in multilayered dry, saturated and unsaturated isotropic poroelastic media. Smeulders’ extension of Biot’s poroelastic theory is used to incorporate unsaturated porous media with a small gas fraction. A wide range of problems in geophysical and civil engineering can be treated, ranging from amplification of plane harmonic waves, dispersion and attenuation of surface waves to transient wave propagation due to a forced excitation. The effect of full or partial saturation on wave propagation in a poroelastic layered halfspace is demonstrated in a numerical example, in which the layering is caused by a moving ground water table.