ABSTRACT
One of the important characteristics of geomaterials is that the material is composed of solid, liquid, and gas in general. In this chapter, governing equations for the analysis including balance laws and constitutive equations are presented based on the theory of porous media, that is, an immiscible mixture of solid and “uids. First, governing equations for “uid-solid materials are shown, then in Section 2.2, the governing equations for gas-liquid-solid three-phase materials are formulated. In Section 2.3 the equations for the unsaturated saturated soils are presented.
