Research On Laws Of Overlying Strata Movement And Subsidence In Close Multiple-seams Of Qianjiaying Mine

Taking the Multi-Seams Qianjiaying Mine as the research object,the subsidence and migration of overlying strata during mining are studied through theoretical analysis,similar simulation and numerical simulation test.The main conclusions are as follows.1)Analysis of Similarity Simulation Results of the close Multi-SeamsUnder the condition of applied load at the top of the model,similar simulated mining tests are carried out for the close Multi-Seams located at a depth of-638m-440 m.During the mining of the upper coal seam,the law of collapse of the overlying strata is symmetrical,and the stress is released in the overlying strata of the goaf.The stress concentration area is mainly located in the position before and after mining.The overlying strata in the upper coal seam appears many times of settlement deformation.Subsidence again of overlying strata in each seam mining,and the stress releass on both sides of the upper coal seam.The more severe the settlement is near the goaf area.2)Simulation of mining in close Multi-Seams with numerical simulation.During the mining process of the 1357 W coal seam,the plastic zone in the overlying strata of the goaf gradually expands,A large displacement change occurs in the goaf,the area of the subsidence area gradually increases,and the coal pillar around the goaf has a stress concentration area.During the mining process of the three lower coal seams respectively,there is no obvious change in the displacement field of overlying strata,The plastic zone has no obvious extension and extension.The plastic zone located in t As the mining progresses,Due to the multiple deformation of the overburden rock,the stress concentration areas on both sides of the goaf expand and converge,and the stress release area underneath expandsThrough similar simulation and numerical simulation tests,the settlement displacement and stress variation during the mining of Qianjiaying multi-coal seam are prospected,providing some references for the safe mining of multiple coal seams.