Engroove Pressure Relief Of Surrounding Rock And Parameter Optimization In High Stress Soft Rock Roadway

Based on the characteristics of high stress soft rock roadway easy to damage and difficult to support,through the basic assumptions of viscoelastic mechanics analysis,analyzed the deformation and failure characteristics of high stress soft rock roadway and the mechanical causes of the roof and floor of the roadway and the failure of the two sides.Through the comparison of the control technology of deformation and failure of high stress soft rock roadway,introduced the pressure releasing slot technology.analyzed the pressure relief mechanism of the pressure relief groove from the change of pressure relief area and roadway support pressure after the excavation of the pressure releasing slot,and summed up the reasonable use conditions of pressure releasing on the basis of previous experience.Using FLAC3D numerical simulation software and similar simulation test technology on the simulation test of pressure relief effect of the pressure releasing slot in different depth,different position,different groove depth and different Notch height of four parameters,draw the following conclusions:(1)The pressure relief effect of the pressure relief groove becomes better and better with the increase of the buried depth of the mine,and the pressure relief groove is more suitable for the mine with high depth and high ground stress.(2)The pressure relief groove through the redistribution of stress in the surrounding rock,strength condition change of surrounding rock stress concentration and stress concentration peak transfer point to change the surrounding rock,and the weakening of the surrounding rock,and ultimately achieve the purpose of protecting the stability of the roadway.(3)The optimum parameters of the pressure relief groove are obtained by comparing the unloading effect of the pressure relief groove under different parameters:the reasonable groove depth should be controlled at half times of the tunnel diameter,the notch height should be controlled in 0.15 times the height of the straight wall,The position of the pressure relief groove on the straight wall has little effect on the deformation and failure control of the roadway,only for the peak value of the stress concentration of the roof.