Energy Distribution of Shock Wave in Deep Rock Mass Blasting

In-situ stress has a significant effect on the distributions of the rock mass stress induced by explosion and the explosion energy. To elucidate the distribution characteristics of explosion energy in deep rock mass, the distribution of rock mass stress under the action of in-situ stress and explosion load is calculated using the superposition principle. Subsequently, the failure characteristics of deep rock mass under shock waves are determined using the rock mass failure criterion. The proportions of shock wave energy that causes blasting cavity expansion, radial crack propagation, and rock mass elastic deformation under different conditions are analyzed. Furthermore, a numerical simulation method is employed to investigate the impact of in-situ stress on the distribution of shock wave energy in the rock mass. The results demonstrate that the characteristics of rock mass, the performance of explosive, and the levels of in-situ stress significantly affect the energy distribution. The proportion of total energy of shock waves transmitted into hard rock (granite) and the proportion of effective energy are smaller than those in soft rock (shale) under high in-situ stress environment. Compared with low-performance explosives, when using high-performance explosives for blasting, the proportion of total energy of shock waves transmitted into granite and the proportion of effective energy are greater. With the increase of in-situ stress, the proportion of shock wave energy for the blasting cavity expansion is basically unchanged, the proportion of shock wave energy for radial crack propagation decreases linearly, and the proportion of shock wave energy for rock mass elastic deformation increases exponentially. The effective energy is relatively small although the proportion of the total energy of shock waves is larger under the higher in-situ stress. The findings can provide a reference for improving the energy distribution of shock wave in deep rock mass blasting and enhancing the blasting effect of rock mass. © 2024 China Ordnance Industry Corporation. All rights reserved.