非连续面空间位态对砂岩洞室损伤破坏特性研究OA

By conducting cyclic loading and unloading tests on a scaled model of discontinuous surfaces sandstone caverns with different spatial states,and combining multiple physical field monitoring techniques such as acoustic emission,resistivity,and digital imaging,the influence of discontinuous surface spatial states on the macroscopic fracture morphology and strength characteristics of sandstone caverns was explored.The results showed that the larger the inclination angle of the discontinuity and the distance from the cavern,the higher the peak strength.The dominant fracture path of surrounding rock is dominated by the spatial state of discontinuous surfaces,the newly formed cracks in the discontinuous surface cavity model of the side wall extend laterally due to stress concentration at the endpoints;the new cracks in the arch foot discontinuous surface cavern model originate from the arch bottom and arch foot,and connect the endpoints of the discontinuous surface.By using PFC simulation technology and moment tensor analysis methods,the influence law of the distance between the discontinuity endpoint and the cavern on the fracture position of the surrounding rock was revealed.The research results systematically elucidate the regulatory mechanism of discontinuous surface spatial states on the evolution of brittle rock cavity cracks,and deeply explore the macro and micro mechanical mechanisms of brittle rock crack nucleation,providing experimental basis and support for the stability evaluation of surrounding rock and disaster prevention and control in underground engineering.