AN INVESTIGATION OF THE EFFECTS OF DEFORMATION-INDUCED PORE PRESSURE ON THE FAILURE OF ROCK LOADED BY A PUNCH
LEDGERWOOD, LEROY WILLIAM, III
Master of Science
Finite Element software is developed which models deformation of poro-elastic-plastic materials. This software is used to model the effects of pore pressure generated during punch indentation on the failure of high and low permeability rocks. The growth of the plastic zone under the punch as a function of load is investigated. A Confinement Transition Load is defined based on a change in character of the growth of the plastic zone. It is shown that in highly permeable rocks, deformation induced pore pressures are always small and do not affect failure. In rocks of low permeability, dilatational hardening effects are measurable, but not large at loads below the Confinement Transition Load.