THEORY OF PLASTICITY OF POROUS MEDIA WITH FLUID FLOW.

Plastic deformation of a porous medium containing moving fluid is analyzed as a motion of a solid-fluid mixture. The effective stress principle and a general form of the yield function - including work-hardening characteristics - and general stress-strain relations are applied to describe the plastic deformation of the solid. The system of governing equations with the number of unknowns being equal to the number of equations is formed. By way of illustration, the theory is applied to the problem of incipient plane plastic deformation of a Coulomb material.