Theoretical Analysis of Dominant Crack Propagation in Hazardous Rock Masses under Blasting Loads

The propagation of cracks in fractured rock masses under explosive loading is a key issue in slope stability and blasting design. To address this problem, this study establishes a theoretical framework for predicting the propagation paths of dominant cracks. Based on the energy dissipation principle and fracture mechanics, single- and double-dominant crack extension models were developed to analyze the influence of explosive loading on crack propagation. The models incorporate the effects of initial stresses, explosive pressures, and the mechanical properties of the rock mass. Numerical simulations using 3DEC were conducted to validate the theoretical models. The simulation results were found to be in good agreement with the theoretical predictions, confirming the reliability of the proposed models in simulating crack behavior under blast loading. A key parameter analysis revealed that explosive detonation pressure, rock fracture toughness, and crack orientation significantly influence crack initiation, growth, and the overall extension path. The findings of this study provide a comprehensive understanding of crack propagation in fractured rock masses subjected to explosive loading. The proposed models offer a promising tool for optimizing blasting operations in rock mass engineering, enabling better control of rock slope stability and improved efficiency in excavation and demolition processes.