Study on the Development and Distribution Rule of Tensile Shear Fracture Propagation Angle of Fractured Rock Mass Under Seepage Pressure

Abstract

In order to study the development and distribution rule of tensile shear fracture propagation angle of fractured rock mass under seepage pressure, the shear-fracture model of single-fractured rock mass under seepage-stress is established, and the functional relationship between fracture expansion angle and fracture angle, confining pressure and seepage pressure is derived. Then based on RFPA-Flow software, the simulation verification of the crack expansion angle expansion rule is carried out. The simulation results verified the feasibility of the fracture propagation rule obtained by theoretical analysis to some extent. (1) In the case of single-fractured rock mass under seepage pressure, the fracture expansion angle increases with the increase of the seepage pressure in the fracture at a certain fracture angle and confining pressure; (2) In the case of a certain seepage pressure and a fracture angle, as the confining pressure increases, the fracture propagation angle also increases; (3) In the case of a certain seepage pressure and confining pressure, as the fracture angle increases, the fracture propagation angle decreases; (4) The rock fracture expansion does not extend completely along the fracture propagation angle due to the influence of confining pressure, seepage pressure and fracture angle. Generally, fractures will first develop along the direction of the fracture propagation angle, but ultimately along the direction of the maximum principal stress to form a fracture. The research results have some complementary and verifying significance for the research of rock fracture damage mechanism.