Spatial and material description of some processes in rigid and non-rigid saturated and unsaturated soils

This paper describes some aspects of the composition of soils, the kinematics of the solid phase, and the movement of the liquid and gaseous phases. In section 2 concepts describing the composition of the soil are introduced. Section 3 deals with the deformation and motion and the balance of mass of the solid phase. In section 4 the balances of mass and momentum for the liquid and gaseous phases are introduced. In sections 5 and 6 some aspects of fluid flow in, respectively, rigid and non-rigid soils are discussed. In section 7 some conclusions are given and possible extensions of the theory are mentioned.