Abstract:Based on the theory of cellular automata,evolving cellular automata(ECA) model is set up considering the fundamental of rock mechanics. In the ECA model,the strain-stress relations of the brittle rock are considered to agree with the perfect elastic constitutive law in meso-cosmic view,but in the macroscopically view,the brittle rock is a kind of nonhonmogeneous material and its nonhonmogeneous distribution is assumed as Weibull distribution. Breaking out the limit that the CA model only consists of one kind of cell,a neighborhood model with two kinds of cells is brought forward in the ECA model. There in,one is the node cell and the other is triangular cell. Displacement,force,stress and strain are taken as basic variables of the system. The tensor and scalar are defined at the triangular cell and the vector at the node cell. In the ECA system,the triangular cell and the node cell are taken as neighborhoods with each other and evolved according to the local international rules. The tensile failure and shear fracture are taken into account by the triangular cell¢s evolving followed the failure rules which are on the basis of the modified Mohr-Coulomb criteria. According to the above-mentioned method,the simulation of the loading and failure process are carried into execution.