冲击地压矿井近距离煤层采空区下回采巷道合理错距研究
Study on reasonable offset of mining roadway under close distance coal seams goaf of rock burst mine
-
摘要: 针对近距离煤层上层煤为采空区及遗留30 m煤柱情况,以葫芦素煤矿2-1煤层及 2-2煤层煤为研究背景,建立上层煤采空区及遗留煤柱受力的力学模型,分析了上层煤区段煤柱下岩层的应力分布状态,研究了近距离煤层采空区下回采巷道布置的合理错距。研究表明:保护层开采后实现充分卸压后,最佳内错距离应为80 m;从上覆遗留煤柱的影响范围来看,最佳内错距离为40~80 m;从对上层煤巷道的影响程度考虑,最佳内错距离宜大于80 m,当内错距离取160 m时,下工作面开采对21101回风巷的影响最低,综合4种不同的角度,对影响范围取交集计算,最终确定22103首采工作面的最佳内错距离为80 m。Abstract: Aiming at the situation that the top coal of the close distance coal seams is goaf and the remaining 30 m coal pillar, taking the 2-1 coal seam and 2-2 coal seam of Hulusu Coal Mine as the research background, the mechanical model of the upper coal goaf and the remaining coal pillar under force is established, the stress distribution state of the strata under the coal pillar in the upper coal section is analyzed, and the reasonable spacing of the stoping roadway under the close distance coal seams goaf is studied. The research shows that the optimal offset distance should be 80 m after the protective layer is fully discharged; from the influence range of the overlying coal pillar, the optimal offset distance is 40-80 m; considering the degree of influence on the upper coal roadway, the optimal offset distance should be greater than 80 m; when the offset distance is 160 m, the lower working face mining has the lowest influence on 21101 return air alley. By combining 4 different angles and calculating the intersection of the influence range, the optimal offset distance of the first working face of 22103 was finally determined to be 80 m.