ABSTRACT
Poroplasticity begins with poroelasticity, which deals with reversible deformation of a fluid infiltrated porous, fractured material that allows for fluid flow through connected voids. Poroplasticity implies deformation beyond the elastic limit as in conventional plasticity theory. In soil mechanics, the connected void space consists mainly of pores between solid particles. In rock mechanics, the connected voids may also be pores but are most likely to be cracks, fractures, and joints. Effective stress allows for mobilization of frictional resistance to shear along a contact plane; the pore fluid offers no shear resistance. Consequently, the properties of joints and intact rock between must be considered in combination to form properties of an equivalent material. The poroelastic/plastic finite element code incorporated a special feature that allowed for desaturation. Excavation by blasting in rock is almost instantaneous and allows expansion of excavation walls into the newly formed opening.
