To explore the influence of fracture geometric parameters (inclination angle, length, and spacing) on mechanical characteristics, crack propagation, and failure mode, uniaxial compression experiments are carried out on double‐fractured rocks. The failure process was analyzed by PFC 2D numerical simulation software. The results show that (1) with the increase in the inclination angle for the secondary fracture, the compressive strength of the specimen changes in “M” shape. The compressive strength of the specimen changes in “V” shape with the increasing of the spacing between the primary and secondary fractures. With the increase in the length of the secondary fracture, the compressive strength of the specimen decreases. (2) When the secondary fracture angle is perpendicular to the loading direction, the number of cracks is relatively small. When the secondary fracture angle is parallel to the loading direction, the number of cracks increases. When the fracture spacing is 12 mm, the number of cracks generated during the failure of the specimen is relatively small. With the increase in the secondary fracture length, the crack number of the specimen decreases gradually. (3) The tension–shear property of the specimen is only affected by the inclination angle of the secondary fracture, while the number of rock bridge crack penetration is mainly affected by the length and spacing of the secondary fracture. Therefore, the nonisometric fracture failure mode is divided into five types according to the tensile–shear property of rock bridge cracks and the number of rock bridge fissure penetrations.
Huang et al. (2025) studied this question.