Study on the Blasting Damage Range of Rock Mass under the Action of Ground Stress

To investigate the influence of ground stress on the fracture distribution and damage characteristics of blasted rock masses, this paper conducts a quantitative analysis of the radius and distribution characteristics of the damage zone under varying ground stress conditions. Using ANSYS/LS-DYNA analysis software, a numerical model of single-hole blasting was established to analyze the dynamic evolution of the stress field around the borehole under ground stress. Based on the numerical simulation results, a formula relating the stress attenuation coefficient to ground stress was obtained through nonlinear fitting. Combined with theoretical analysis, a predictive model for the radius of the smash zone and the crack zone of the blasted rock mass under ground stress was developed. The results indicate that ground stress not only inhibits the development of blasting damage but also guides the direction of crack propagation. Under isobaric ground stress, the crack zone is circularly distributed, with the area decreasing nonlinearly as ground stress increases. Under unequal pressure ground stress, the crack zone is elliptically distributed, with fractures primarily propagating along the direction of the maximum principal stress. As the unequal pressure coefficient increases, the ellipse’s eccentricity continuously increases.