Simulation of Hydraulic Fracture Best Slotted Position of Hard Roof

For the geological structure of thick coal seam, undulating angle, long hanging arch, extremely hard roof and stable overall structure, the stress tends to concentrate regionally, and high energy also accumulates in the roof, which increases the risk of rock-burst. This article takes the hydraulic fracturing technology to break the overall structure of hard roof, and release the energy through damaging it. Combined with seepage-stress coupling analysis software F-RFPA^2D, the best slotting position has been simulated by using roof directional hydraulic fracturing technology. Conclusions are drawn as follows. Between the main roof and the upper boundary，the slot locates in the middle of the main roof or closes to the immediate roof，and crack extension works best; in the middle of the main roof，two slots are in the level of symmetric distribution, and crack extension works best too.