Peridynamics simulating of dynamics crack propagation in rock mass under blasting load

Abstract

It is important to study the crack propagation and failure criterion of fractured rock masses under dynamic blasting loads to ensure the safety and stability of tunnels constructed using the drill-and-blast method. Based on the idea of conventional peridynamics, a peridynamics constitutive model of the pull-compression composite failure of rock materials and a peridynamics simulation method for crack propagation in a fractured rock mass under a blasting load were established. In addition, the criterion for the stress wave incident angle and in-situ stress state for crack propagation in a rock mass were investigated. The incident angle of the stress waves was found to affect the crack propagation. When the incident angle was 0°, new cracks propagated parallel to prefabricated cracks. When the incident angle was 15°-75°, wing cracks formed at the tips on both sides of a prefabricated crack, and the initiation and propagation angles of these new cracks increased with the incident angle. The in-situ stress affected the propagation direction of an explosive-generated crack and the range of the fracture zone. When unidirectional stress was applied, the radial main crack expanded along the direction of the stress, and the range of the fracture zone decreased with an increase in stress. The applicability and accuracy of the proposed dynamic disturbance peridynamics simulation method for solving the problem of dynamic failure and crack growth in a rock mass were verified based on previous physical and model test results.