Study on the effect of joint dip angle on roadway deterioration and regional control of surrounding rock

In order to solve the problem of surrounding rock control of joint development roadway, theoretical analysis, numerical simulation and field measurement methods were used to study the deterioration effect of joint dip angle on roadway surrounding rock, the deformation characteristics and development law of surrounding rock of large section roadway with joint development were analyzed.The results show that the joint weakens the strength of the rock mass and make it appear anisotropy, the surrounding rock of jointed roadway presents fragmentation, low bearing capacity and weak stability; rock masses with small joint angle(from 0° to 45°) develop joints into tensile cracks under load, and then tensile fracture, overturning and rotation occur, so the rock masses exhibit significant mixed tensile and shear failure, which makes the rock mass in the mine roadway catastrophically unstable. This paper puts forward the principle of regional control of surrounding rock in joint development and the control technology of modified reinforcement of surrounding rock and combined support of anchor, net and cable. The maximum subsidence of the roadway roof is 120 mm, and the maximum movement of the two sides is 90 mm, the deformation of roadway is small and the deformation of surrounding rock with joint development has been effectively controlled.