Study on stability of goaf overlying strata with "110 construction method" in Shennan mining area

Based on the engineering charateristics of Shennan mining area, the structural features of the main rock layers in the mining area were analyzed by rock microscopical laboratory experiments, field monitoring, physical simulation experiments (DIC monitoring and strain monitoring), and FLAC3D numerical simulation.The evolution laws of the displacement and stress fields of overlying rock in goaf under the mining technology of " 110 construction method" (a new mining technology without coal pillar) were obtained.The research results show that the rock mass in Shennan mining area has a high degree of joint fracture development and the quality grade of rock mass is low.The "110 construction method" provided a improved gob-side entry retaining in the mining of coal seam with kilometer level burial depth by using the fragmentation and expansion effect of rock mass and high constant resistance energy absorbing anchor cable compensating mechanical support characteristics.The settlement displacement intensity of the mining area under the "110 construction method" is central area > tangent side area > non-tangent side area.The combined mining technology of "110 construction method" consisted with roof cutting, pressure relief and high constant resistance energy absorbing anchor cable is capable providing scientific bases for the stability study of large deformation and weak surrounding rock in underground space engineering other than coal mining.