Damage evolution mechanism in production blasting excavation under different stress fields.

Deep rock mass stores large amounts of energy. Energy accumulation, dissipation, and release during the deformation and failure of rock mass occur when the rock mass is excavated via the drilling and blasting method. According to the energy effects, failure pattern, and effect of the strain rate on the rock strength, a Johnson–Holmquist rock (JHR) model was established by combining the energy-based tensile–compressive damage model and the Johnson–Holmquist ceramic model based on the coupling method for tensile–compressive damage in a rheological-dynamical analogy model. To apply the same method to the damage evolution mechanism of deep rock mass, the JHR model was incorporated into the LS-DYNA software. Subsequently, the self-developed numerical model was employed to investigate the damage evolution in the production blasting excavation of stopping holes under different stress fields. According to the failure law, the challenges in rock-mass excavation were analysed. This study provides a basis for the analysis and research regarding the blasting design in deep rock-mass excavation.