Yan’an Checun Coal Industry(Group) Co. , Ltd.
Yan’an Hecaogou No. 2 Coal Mine Co. , Ltd.

为了探究浅埋极薄煤层切顶卸压无煤柱开采与常规留煤柱开采覆岩运移与地表损伤区别,以子长矿区浅埋极薄煤层为背景,基于关键层理论,得到了硬岩破断距及覆岩的垮落高度临界值的计算公式,结合3DEC数值模拟及现场试验,对比分析了无煤柱开采与留煤柱开采条件下浅埋极薄煤层覆岩运移破断及地表损伤特征,确定了极薄煤层覆岩两带高度。结果表明:当工作面回采达到60m时,两带发育高度基本稳定,当大于60m时,工作面后方覆岩裂隙由开裂逐渐闭合,裂隙区随工作面回采向前方移动,两带高度稳定在24.6~27.7m;相较于常规留煤柱开采,切顶留巷无煤柱开采方式下覆岩呈连续移动变形,可有效修复煤层开采工作面两侧非连续移动变形导致的覆岩裂隙及地表损伤裂缝,消除了常规留煤柱开采方式下相邻工作面间区段煤柱两侧覆岩裂隙,现场观测较好地验证了该结果。

In order to explore the difference between the overburden migration and surface damage in the shallow extremely-thin coal seam non-pillar mining by roof cutting and pressure relief mining and the conventional coal pillar retaining mining, based on the key stratum theory and the shallow extremely thin coal seam in Zichang mining area, the formula for calculating the critical value of the hard rock breaking distance and the overburden caving height is obtained.Combining with 3DEC numerical simulation and field tests, the characteristics of overburden migration and surface damage in shallow extremely thin coal seams under the conditions of non pillar mining and coal pillar retaining mining are compared and analyzed, and the heights of the two overburden zones in extremely thin coal seams are determined. The results show that when the mining face reaches 60m, the development height of the two zones is basically stable. When the mining face is larger than m, the cracks in the overburden behind the working face gradually close from cracks, and the crack area moves forward with the mining face, and the height of the two belts is stable at 24. 6 ~ 27. 7 m; compared with the conventional coal pillar retaining mining, the overburden under the roof cutting and entry retaining mining without coal pillar is continuously moving and deformed, which can effectively repair the overburden cracks and surface damage cracks caused by the discontinuous movement and deformation on both sides of the coal seam mining face, and eliminate the overburden cracks on both sides of the coal pillar in the adjacent working face section under the conventional coal pillar retaining mining method. The results are verified by field observation.

延安市科技“揭榜制”计划项目(2021JB-07)

李斌,陈金拴,贺炳伟,等.浅埋极薄煤层无煤柱开采覆岩运移与地表损伤特征研究[J].煤炭工程,2024,56(4):104-111.