Practice of rock burst prevention and control based on high-pressurehydraulic drilling and cutting technology along bedding

In ocler to improve the efficiency and effectiveness of pressure relief in prevention and control of rock burst the working face’s high stress area，it has put forward the use of bedding drilling technology of high pressure water for unloading process in advance in rock burst danger area of full-mechanized caving mining face. It has avoided defects of drill hole pressure relief and coal seam water injection and blasting pressure relief and so on and analyzed theoretically unloading principle and feasibility of the technology. This has also verified pressure-relief effect of numerical simulation and electromagnetic radiation. Results show that:①the layout of drill of bedding drilling technology of high pressure water is along the tendency of mining face and the coal layers of bedding.It cuts and breaks the coal by highly shaped water jet which pressure is higher than 30 MPa，and forms pressure relief space. It also infiltrates and weakens the coal body. The drill has formed rupture zone，plastic zone and elastic zone by inside and outside，and as the amount of deformation and the plastic zone and ruptured zone continuously increased，the zone has deformed and caved leading to accumulated elastic energy releasing，and the static load of coal and rock has become lower. The condition of rock bursts has eliminated，and rock burst has be prevented. ②The bedding drilling technology of high pressure water has adopted the combination of fixed point and repeated dynamic drilling and the combination of axial and radial movement of the drill pipe，which not only guarantees the stability of drilling，but also forms multi-segment and disc-shaped pressure relief space and continuous relief holes. In the coal seam，pressure relief space with radius of 300-400 mm can be formed，and the output of coal can reach 2.0-3.5 t.③The numerical simulation results show that the average decrease of the internal stress value of the coal body is 68.6% and the average decrease value of the electromagnetic radiation monitoring is 60.92% by using Bedding drilling technology of high pressure water.After use，the stress reducing area of lane has dramatically expanded and the internal stress value of coal has significantly reduced. The unloading effect is good.