Numerical simulation of dynamic fracture properties of rocks under different static stress conditions

When underground cavities are subjected to explosive stress waves, a uniquely damaged zone may appear due to the combined effect of dynamic loading and static pre-load stress. In this study, a rate-dependent two-dimensional rock dynamic constitutive model was established to investigate the dynamic fractures of rocks under different static stress conditions. The effects of the loading rate and peak amplitude of the blasting wave under different confining pressures and the vertical compressive coefficient (K-0) were considered. The numerical simulated results reproduced the initiation and further propagation of primary radial crack fractures, which were in agreement with the experimental results. The dynamic loading rate, peak amplitude, static vertical compressive coefficient (K-0) and confining pressure affected the evolution of fractures around the borehole. The heterogeneity parameter (m) plays an important role in the evolution of fractures around the borehole. The crack propagation path became more discontinuous and rougher in a smaller-heterogeneity parameter case.