Numerical simulation of dynamic cracks propagation of rock under blasting loading

The influences of the blast loading rate, the distance from the guide hole to the free boundary and the radius of the guide hole between the two charge holes, on the dynamic propagation of cracks in rock were studied using realistic failure process analysis (RFPA-dynamic). The results show that, as the loading rate decreases, the crushed zone around the charge hole is gradually reduced; the position of the crack initiation moves gradually from the crushed zone to the charge hole; and the number of small branch cracks gradually decreases while the length of the main crack increases. Due to the influence of the free boundary, the cracks that were previously downward now gradually bend in the horizontal direction, and this tendency becomes more observable as the distance from the charge hole to the free boundary gets shorter. As a result of the guidance of the guide hole, the cracks close to the guide hole gradually curve to the guide hole and, at the same time, a crack is formed at both ends of the guide hole wall that propagates to the charge hole. The radius of the guide hole has no obvious effect on the guiding role, but the nonuniformity of the material does have a significant effect on the way the cracks propagate. © 2016, Editorial Board of EXPLOSION AND SHOCK WAVES. All right reserved.