Abstract: In the study, we calculated the pillar size of 4# coal seam with the traditional method, the analysis result showed that repeated calculation was existed in calculation of the central elastic area of the waterproof pillar in inclined seam, which results in oversized waterproof pillar left. In order to improve the disadvantages of traditional methods, in the premise of ensuring safety, we calculated the yield zone size of 4# seam, considered the impact of the overburden rock moving angle and we obtained the reasonable waterproof pillar size after the design method had been optimized. In order to further improve the recovery rate in the mining area, we comprehensively analyzed the common problems of coal pillar design and proposed optimization. Findings showed that the size of waterproof coal pillars after the design was optimized is only 42.42% of the size calculated in traditional method. Integrated the triangle coal loss of the slope segment and combined with a waterproof coal pillar size, coal loss after optimization is only 45.42% of the one in traditional method. It is calculated according to the push length of the mining area designed that nearly more than 1.58 Mt of coal can be mined between the adjacent faces. In addition, the recovery technology from the slope sections can improve the stability of equipments, which caused by the large inclination in working face.

Key words: inclined coal seam, waterproof pillar, overlying rock moving angle, yielded zone, roadway layout