Abstract:By using Rock Failure Process Analysis code (RFPA2D),the slip failure process of rock sample is numerically studied. The rock samples are considered as brittle and heterogeneous materials. The phenomena of progressive failure leading to collapse in sheared rock samples are numerically demonstrated. It is shown that shear face is the main feature of the slip failure mode. The shear face is initiated first in one side of the sample and to the center and then to another side. Finally,a macro shear face mode is observed and there are relationships between failure face fractal and mechanical behavior.