Study on the influence of geometrical parameters of discrete fracture network on mechanical parameters of fractured rock mass

In order to understand the influence of the geometric parameters of discrete fracture network on the mechanical parameters of fractured rock mass, discrete fracture networks with different structural characteristics are constructed, and the corresponding synthetic rock mass model is established.The mechanical parameters of the synthetic rock mass model are obtained through uniaxial compression numerical test, and the influence of the geometric parameters of discrete fracture network on the mechanical parameters of fractured rock mass is analyzed.The results show that with the increase of fracture density P₃₂, uniaxial compressive strength, elastic modulus and peak strain decrease approximately linearly, and Poisson’s ratio increases approximately linearly.With the increase of the mean value of fracture dip angle, the uniaxial compressive strength, elastic modulus and peak strain first decrease and then increase, and the Poisson’s ratio first increases and then decreases.When the fracture dip angle is 60°, it reaches the extreme value.For the distribution characteristics of fracture dip angle, when the mean value of fracture dip angle is 60°, the uniaxial compressive strength, elastic modulus and peak strain decrease with the increase of Fisher distribution constant, and the Poisson’s ratio increases with the increase of Fisher distribution constant.For the mean value of other fracture dip angles, Fisher distribution constant has little effect on the mechanical parameters of fractured rock mass.The sensitivity analysis results show that the uniaxial compressive strength is the most sensitive to the geometric parameters of discrete fracture network and the elastic modulus is the least sensitive.