Reasonable Alternate Distance of Combined Mining Face of Close-distance Seams at Xinzhi Coal Mine

During the mining process of close-distance seams, the interaction between upper and down layers, the special layout of the roadway and the difficulty in supporting, the very quick succession of successive faces, the low production efficiency and other issues are plaguing the efficient coal mine safety production. The pitch of 9#and 10#thin coal seams of Huozhou Coal Electricity Xinzhi Coal Mine of Shanxi Coking Coal Group is only 1.71m, which is taken as the engineering background of our study of the close distance coal seams.Some relatively mature theory on the close-distance seams is used to calculate and analyze the alternate distance of 9#seam and 10#seam combination mining face. The FLAC3D software is used to simulate the stresses in 10#seam and 9#seam under the combination mining with different alternate distances. The result shows that, during the combination mining of Xinzhi Coal Mine 10#seam and 9#seam, the reasonable alternate distance should not be less than 35 m. The research results show how to improve the coal resource recovery ratio,and ensure the safe and efficient production of coal enterprises.