Xinwen Mining Group Co. , Ltd.

针对上行开采覆岩运动可能会使上覆煤层的整体性遭到破坏,造成上覆煤层无法开采的技术难题,以某矿9煤工作面开采对上覆5煤的影响为工程背景,采用理论分析、数值模拟、相似材料模拟等手段,研究了近距离煤层下煤开采后上覆岩层覆岩破坏情况、岩层裂隙发育规律及工作面矿压显现规律等问题,得到如下结论:近距离煤层下伏9煤开采后上覆岩层塑性区范围,其中三带判别法得垮落带高度平均9m,导水裂隙带高度36m;比值分析法K为19.99,大于中硬岩层7.5;围岩平衡法得上覆5煤安全开采的必要层间距为45m,远小于5煤与9煤层间距60m;数值模拟表明,近距离煤层下伏9煤工作面开采后上覆5煤位于下煤层开采后形成的塑性区域内,在留设保护煤柱区域内不会存在应力集中现象;相似模拟表明,近距离下伏9煤开采后,5煤最大下沉值为10mm,模型垮落带高度基本在15cm左右,符合矿山压力及覆岩运动发展规律;该矿近距离下伏9煤开采后上覆5煤开采是可行的。

In upward mining, the overlying rock movement may damage the overall integrity of the overlying coal seam and make it unminable. Based on the engineering background of the impact of the mining of the 9# coal seam on the overlying 5# coal seam in a certain mine. Theoretical analysis, numerical simulation, and similar material simulation are used to study the damage of the overlying rock strata, the development law of rock fractures, and the behavior law of the working face’s rock pressure after coal mining in close range coal seams. The results are as follows, after the 9# coal seam is mined, the three zone discrimination method obtained an average height of 9 m for the collapse zone and 36 m for the water conducting fracture zone;the ratio analysis method K is 19. 99, which is greater than 7. 5 for medium hard rock layers; the necessary layer spacing for safe mining of the overlying 5# coal seam using the surrounding rock balance method is 45 m, which is much smaller than the 60 m spacing between the 5# coal seam and the 9# coal seam. Numerical simulation shows that the overlying 5# coal seam of the 9# coal face are located in the plastic area formed after the mining of the lower coal seam, and there will be no stress concentration phenomenon in the area where protective coal pillars are left. Similar simulations indicate that after mining the 9# coal seam, the maximum subsidence of the 5# coal seam is 10mm, and the height of the model collapse zone is basically around 15 cm, which is consistent with the development laws of mining pressure and overlying rock movement. The relevant research results demonstrate the feasibility of mining the overlying 5# coal seam after mining the 9# coal seam.

1 地质概况
2 理论分析
2.1 三带判别法
2.2 比值分析法
2.3 围岩平衡法
3 数值模拟
3.1 模型建立
3.2 围岩塑性区分析
3.3 区段煤柱留设覆岩规律分析
4 物理模拟实验
4.1 物理模拟相似条件
4.2 模型开挖及实验数据分析
5 结 论

张志勇, 刘媛媛, 李延锋. 近距离下煤层上覆岩层裂隙发育规律与上行开采研究 [J]. 煤炭工程, 2024, 56(1): 113-118.