Study on fracture parameter calibration and failure characteristics of rock with hole and crack

Abstract Cracks within the surrounding rock of roadways significantly affect their stability and failure characteristics. Investigating the failure modes of roadways under different crack distribution characteristics provides a theoretical basis for roadway support design. This study, based on the principle of superposition and the Mohr‐Coulomb criterion, derives calculation equations for the stress intensity factors of cracks and the radius of the plastic zone under the influence of stress concentration in roadways. Numerical simulations of roadway failures under varying crack distribution characteristics were conducted using PFC 2D . The evolution patterns of crack fracture parameters under different lateral pressure coefficients and material properties were analyzed. The results show that the surrounding rock of the roadway develops tensile and shear cracks due to stress concentration. Under the influence of overburden load, the rock mass cracks evolve into wing cracks and coplanar cracks. The development and intersection of these four crack modes are the primary reasons for differences in roadway‐bearing capacity and failure modes. A larger distance between the roadway and cracks, shorter crack lengths, larger crack positional angles, and steeper crack dip angles effectively delay the time and distance of crack intersections, reduce the number of stress curve transitions, shift AE signals to a later stage, and enhance the strength and stability of the roadway. This study provides a foundation for evaluating roadway stability and selecting support parameters.