关键词: 深部开采, 近距离煤层, 类孤岛工作面, 离散元模拟, 卸压开采

Abstract: In deep mines, an analogy ‘isolated island’ working face with one side of the local coal seam and one side of the lower coal seam is easily produced in the later stage of close-distance coal seam group mining in the upper coal seam, and its position design has a direct impact on the mining intensity of the working face. Through on-site investigation and analysis, the ‘下’ type structure of the surrounding rock of the analogy 'isolated island' face of the close upper coal seam is proposed and the potential mining risk factors are elaborated. Three types of layout schemes are proposed based on the positional relationship between this analogy ‘isolated island’ face and solid coal in the lower coal seam, and eight kinds of island surface layout models are established based on discrete element numerical software. It is concluded that the solid coal in the coal seam should be staggered downwards on the analogy 'isolated island' face, and when the staggered distance is about 25 m, the peak stress increase coefficient of the solid coal seam along the trough decreases to below 1.5, and the stress of the coal pillar seam apparently decreases, which is suitable for this arrangement. Considering that there is a thick and hard roof on this analogy ‘isolated island’ face, the method of reasonable layout+ roof pre-splitting+ re-mining after pressure relief is put forward, which provides reference and reference for related projects on site.