Mine pressure behaviour law and feasibility study of upward mining for short distance coal seams in Fan'gezhuang coal mine

Based on the upward mining of short distance coal seams in Fangezhuang coal mine of Kailuan group, this paper studies the mine pressure behavior law and strata movement in the upward mining process of coal seam 5 and coal seam 7 by comprehensive use of numerical simulation, empirical analogy, probability integration and other methods.The interaction between short distance coal seams is studied, and the feasibility of upward mining is evaluated.The results show that a stress relief area appears above the goaf, and the subsidence of the roof increases continuously to form a roof subsidence area in the mining process of coal seam 7.The coal seam 5 sinks 3.1 m under the influence of the mining of coal seam 7.In the mining process of coal seam 5, the range of the roof stress relief area and the roof subsidence are greater comparing with coal seam 7.The stress concentration in the gob boundary of coal seam 7 shifts to the gob boundary of coal seam 5.The upper coal seam is 15 m above the caving zone of the lower coal seam and located in the upper stratum balance area of the water flowing fractured zone, which has the conditions of upward mining.On the basis of the research results, the reasonable layout scheme of panel 2551N for coal seam 5 is given.This research obtains certain theoretical significance and engineering value.