Research On Bolt (Cable) Support For Prevention Of Integral Slipping Type Coal Bump

With the expansion of coal resources mining to the deep,the coal bump and other dynamic phenomena are characterized by more intense,significantly more frequent,more difficult to manage,and greater threat to safety production.The research of anti-scour technology has important theoretical significance and practical value for solving the coal bump in roadway.The bolt(cable)anti-scour support technology of slipping type coal bump is studied by using theoretical analysis,laboratory tests,numerical simulation and engineering application practice.On the basis of studying the characteristics of the overall slip-type impact ground pressure disaster,the scour power source and scour impedance factors are clarified according to the analysis principle of unloading-slip mechanism of coal bump.The results of the direct shear test of in-situ coal rock samples show that the impact-slip interface at the sampling site is in the coal.Through the direct shear test of coal,the residual friction angle of coal is determined to be 39.29°,which is the key parameter for the calculation of coal scour energy dissipation.According to the principle of sawtooth,the mechanical analysis model of scour slip interface is established,and the calculation method of impact slip interface strength is proposed.The results of the anchoring strengthening of the coal-rock interface show that the angle between the bolt and the coal-rock interface can affect the strength of the impact slip interface,and when the angle is less than 45°,the bolt(cable)has the best strengthening effect on the impact slip interface.A large rib spacing rebar bolt with a rib pitch of 50 mm is designed and produces.The laboratory test results show that the yield strength of the bolt under static load is 591.0 MPa,the breaking strength is 722 MPa,and the maximum energy absorption value after breaking is 22.1 k J.The anchoring performance test of the bolt shows that the anchoring performance of the new bolt is at least 15% higher than that of the mine bolt,the anchoring resistance and torque are reduced by 27% and 73%,respectively,and the anchoring agent filling effect is significantly better than that of the mine bolt.Based on the evolution and energy dissipation mechanism of slip-off scour geopressure,combined with the basic parameters of the engineering site,the maximum impact slip distance of the coal body in the test roadway is determined to be 4.14 m.The anti-impact support parameters such as the number of supporting materials,the installation angle of the bolt,the length of the horizontal impact support material,and the anchoring method are clarified.The field application shows that after the new supporting materials and supporting processes,the convergence of the roadway roof and floor and the two sets is reduced by 14.3% and 26.1%,respectively,and the deep part of the surrounding rock is reduced by 21%.In this dissertation,there are 67 figures,8 tables and 136 references,respectively.