Evolution of overburden fracture and water seepage in coal seam group mining an example in Lingxin coal mine

Taking Lingxin Coal Mine as the research object, the combination of physical experiment and numerical simulation analysis was used to study the mining failure of overlying strata and the development of surrounding rock cracks in goaf. The results show that when the underground coal seam mining is not sufficient, the overburden separation is developed, the connected pore area of the overburden failure accounts for about 20% of the total mining area. When the underground coal seam is fully mined, the overburden failure is severe, the overburden failure cracks are interconnected, and the connected pore area increases significantly.