Research on penetration model of rock is one of the most important subjects in coupled hydro-mechanical research. Penetration property of rock is controlled by pores and evolving cracks before the full coalescence of micro-cracks. The former penetration models of rock are set up just based on either crack or pore

so penetration property in the process of cracks spreading can not be properly depicted by them. In allusion to this problem

statistical penetration model is set up with rock damage evolution considered in this paper. The model regards the penetration property in the process of crack spreading as a nonlinear dynamic process

in which effects of both spreading cracks and pores in rock are jointly considered. Therefore

penetration property in the process of crack spreading can be perfectly expressed.