Deformation mechanism and control technology of the external dislocation roadway under the close distance coal seam

In view of the problem that it is difficult to maintain the external dislocation roadway under the close distance coal seam, under the influence of the superimposed stress after the coal mining in the upper layer and before the coal mining in this layer, the plastic failure characteristics, stress distribution and displacement change law of the external dislocation roadway are analyzed by theoretical analysis and numerical simulation, this paper puts forward the three-dimensional joint roof control technology of "broken roof hole+pressure relief hole+high prestressed anchor cable+single hydraulic prop". The industrial test results show that, after the implementation of the technical scheme, the maximum subsidence of the roof of the external dislocation roadway is less than 200 mm, the stress of the anchor cable is less than 230 kN, and there is no roof leakage, the integrity of the roadway is good, and the deformation of the surrounding rock is effectively controlled. This technology can better solve the problem of difficult maintenance of the external dislocation roadway under the close distance coal seam, and promote the safe and efficient production of the coal mine.