Abstract: After excavation of caverns, the surrounding rock mass of them usually generates a lot of stochastic distribution of penetrative cracks which directly affects the stability of surrounding rock mass. It is important to study the deformation and deformation characteristics of rock mass with stochastic distribution of penetrative cracks. Based on linear elastic theory and linear stiffness theory, the computational model of deformation of rock mass with stochastic distribution of penetrative cracks is established by probabilistic approach. Equivalent elastic modulus and equivalent Poisson’s ratio are also presented. The effects of material parameters and geometry parameters of rock and cracks on the equivalent elastic modulus and equivalent Poisson’s ratio of fractured rock mass are studied. The following conclusions can be concluded: the equivalent elastic modulus and equivalent Poisson’s ratio all increase with the increase of elastic modulus of rock. The equivalent Poisson’s ratio increases with the increase of Poisson’s ratio of rock. The equivalent elastic modulus and equivalent Poisson’s ratio all increase with the increase of normal stiffness of cracks. With the increase of shear stiffness of cracks, the equivalent elastic modulus increases, while equivalent Poisson’s ratio decreases. With the increase of mean space of cracks, the equivalent elastic modulus decreases, while the equivalent Poisson’s ratio increases when the mean dip is smaller and decrease when mean dip is larger. With the increase of mean dip of cracks, the equivalent elastic modulus firstly decreases and then increases, while the equivalent Poisson’s ratio firstly increases and then decreases. The model can more comprehensively consider the effects of material parameters and geometry parameters of rock and cracks on the deformation of rock mass. So the model has some reference value in studying deformation of surrounding rock mass of caverns.

Key words: stochastic distribution, rock mass with penetrative cracks, deformation characteristic, equivalent elastic modulus, equivalent Poisson’s ratio