DEVELOPMENT LAW OF WATER CONDUCTING FISSURES IN THE GOAF OF MULTIPLE COAL SEAMS BASED ON SIMILAR MATERIAL SIMULATION - TAKING THE MAJILIANG COAL MINE AS AN EXAMPLE

The development of multiple coal seams may cause a variety of rock movements and damages, which in turn will cause complication of mining conditions and a series of environmental and safety issues. In this paper, taking the Majiliang mine in Datong mining area in China as an example, we systematically explored the overburden structure damage characteristics caused by non-single-layer coal mining, using on-site measurements and material numerical simulation methods. The results show that the height of the water-conducting fissures in the Jurassic coal seams is much smaller than that of the Carboniferous coal-seams. The overburden fissures are relatively developed in the open cut and the front of the working face, and the influence range of the Carboniferous coal seam after mining will spread to the Jurassic goal This in turn will cause secondary deformations in the Jurassic goaf and aggravate the subsidence of the ground. The research results will provide scientific guidance for controlling the intensity of mining and preventing the threat of water accumulation in the goaf.