ABSTRACT
Biot (1956a, 1956b) developed a theory which describes the wave propagation mechanism in the dual-phase medium for the linear elastic regime, by introducing the concepts of mass and viscous coupling in the fluid-solid interaction. It was found that the solution consists of two dilatational waves and one rotational wave propagating in the porous medium with frequency dependent damping factors. Biot’s original formulation was based on the concepts of partial solid stress and partial fluid pressure as defined in Section 2.1. This formulation, together with the elastic constitutive relations, is commonly recognized as the u-U formulation.
