范各庄矿近距离煤层上行开采矿压显现规律与可行性研究

以开滦集团范各庄煤矿近距离煤层的上行开采为背景,综合运用数值模拟、经验类比、概率积分等方法,研究5号煤层和7号煤层上行开采过程中矿压显现和岩层移动规律,分析了近距离煤层间相互影响作用,并对上行开采的可行性进行了评估。研究表明:7号煤层开采过程中,采空区上方出现应力卸压区,顶板下沉量不断增大形成顶板下沉区,5号煤层受7号煤层采动影响下沉3.1m;与7号煤层开采相比,5号煤层开采过程中顶板应力卸压区范围和顶板下沉量都有所增加,且7号煤层采空区边界应力集中出现向5号煤层采空区边界转移的现象;上层煤层处于下层煤层垮落带上方15m以外,处于导水裂隙带的上位岩层平衡区域,具备上行开采的条件。在研究结果的基础上给出5号煤层2551N工作面合理的布置方案,具有一定的理论意义和工程价值。

Mine pressure behaviour and feasibility study of upward mining for short distance coal seams in Fangezhuang 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 behaviour and strata movement in the upward mining process of coal seam 5 and 7. The interaction between short distance coal seams is studied, and the feasibility of upward mining is evaluated. The results show that: (1) In the mining process of coal seam 7, a stress relief area appears above the goaf, and the subsidence of the roof increases continuously to form a roof subsidence area. The coal seam 5 sinks 3.1 m under the influence of the mining of coal seam 7. (2) 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. (3) The upper coal seam is 15m 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.