Study on Water-conducting Fracture Height of Shallow Buried Coal Seam with Thick Loose Bed and Thin Base Rock

Water-conducting fissures formed in shallow seam mining in thin bedrock are easy to cause water resources damage. The determination of the height of water-conducting fissures is the key to avoid the damage of aquifers. Taking 5-20101 working face of Qinglongsi Coal Mine as the research object, the development height of water-conducting fracture zone in coal seam mining is analyzed by physical analogy simulation, theoretical calculation and water injection leak detection method. The research shows that the overburden rock above the goaf after mining forms an arch beam structure, the edge of the arch is a tension stress area, the vertical shear fracture is the main water conduction channel of the stratum, and the water conduction fracture is octagonal distribution; the height of water conduction fracture is 52.3 m to 62 m, with an average of 57.2 m, and the ratio of fracture to mining is 24.2; the development of water conduction fracture is not connected with the Sarawusu aquifer. The production process is not threatened by aquifer irrigation.