坚硬孔洞压裂岩体动态破裂力学响应特征OA

To address the severe rock mass damage and deformation during the hydraulic fracturing pressure relief process in mines,based on elasticity mechanics and impact dynamics,a correlation model between the dissipated energy of rock mass fracture damage and water pressure as well as the equivalent radius of fracture damage was established.Using numerical simulation methods,dynamic hydraulic fracturing-uniaxial static compression coupling numerical tests were conducted on marble specimens with different diameter holes to study the coupling effect mechanism of hole diameter and fracturing step on the mechanical properties and failure characteristics of the specimens.The research results indicate that the dissipated energy of rock mass fracture damage is positively correlated with water pressure and the equivalent radius of fracture damage.The fracture evolution presents three stages:initiation,rapid expansion,and stable expansion.An increase in hole diameter significantly enhances the stress disturbance of the surrounding rock.For rock samples with different fracturing hole diameters,the driving failure mode changes from hole dominance to fracture control and eventually to composite failure due to the differentiation of stress gradient and the competition of weakened interfaces.The peak stress-strain response shows three stages:initial damage instability,main fracture weakening,and residual strength balance,following an exponential decay law.The damage evolution of rock mass fractured by holes is jointly controlled by hole diameter and fracturing step.