Field and simulation study of the rational retracement channel position and control strategy in close?distance coal seams

Different from single coal seam mining, the stress evolution in end mining stage of close-distance seams is extremely complex. The unreasonable position and support lower retracement channel will cause serious deformation damage to surrounding rock. Taking Yanzishan mine as engineering background, failure characteristics under different overlay environments key influencing factors design were discussed by numerical simulation, theoretical analysis, field investigation. results show that coupling superposition upper pillar high dynamic pressure form a dangerous area with severe ground behavior. should be preferentially designed zone A (overlying roadways), followed B end-mining pillar), finally, C section pillar). In addition, rational horizontal distance between make good environment. safety nearest main roadway (end-mining width) greater than range advance abutment pressure. Finally, principle control strategy for proposed. feasibility rationality study are verified industrial applications.