基于3D打印的深部开采中煤矿岩体结构面剪切特性研究OA

The deep rock mass is in an extremely complex stress environment,but with the continuous increase of mining depth,the stress of the surrounding rock in the deep part is redistributed,resulting in high stress behavior in some rock mas-ses.We use 3D printing technology to prepare four sets of structural face shear specimens with different roughness coeffi-cients for the same type of rock specimens,and conduct structural face shear experiments under different normal stresses.The results show that the failure mode of structural face can be basically divided into three stages.When the normal stress is 2.3 MPa,the rock mass is relatively intact and belongs to shear slip failure;When the normal stress is less than 16.1 MPa and greater than 2.3 MPa,the structural face undergoes shear failure along the middle of the undulating body,which is a mixed tensile shear failure;When the normal stress is 20.7 MPa,the overlying rock mass of the specimen is severely dam-aged,resulting in axial splitting failure;As the normal stress increases,when the normal stress is 20.7 MPa,the roughness coefficient does not have a significant impact on the reduction of the peak shear strength of the structural face.Moreover,un-der the same normal stress,the change in roughness coefficient mainly affects the number of cracks generated in the structur-al face,providing a reference for determining the magnitude of the normal stress applied to the specimen.