浅埋近距离煤层重复采动下覆岩隔水层破坏特征分析

Failure characteristics of overlying rock aquiclude under repeated mining of shallow close-distance coal seams

  • 摘要:
    目的及方法 陕北侏罗纪煤田主要赋存浅埋近距离煤层,受重复采动覆岩裂隙活化发育的影响,易贯通隔水层导致其失稳,造成地下水资源流失。隔水层保持稳定是实现保水开采的重要前提,而上行裂隙发育高度和下行裂隙发育深度是判断隔水层是否保持稳定性的重要手段。基于红柳林煤矿4−2、5−2煤层工况,结合数值模拟实验开展研究,研究单一煤层开采和重复采动下裂隙发育规律的隔水层破坏特征。
    结果及结论 结果表明,4−2煤层单一煤层开采时上下裂隙未贯通,隔水层可以保持稳定性;5−2煤层重复采动时,上下裂隙发生贯通,隔水层失稳。因此,为实现该区域保水开采,应采取限高开采、分层开采等措施。

     

    Abstract: The Jurassic coalfield in northern Shaanxi is mainly composed of shallow buried close-distance coal seams. Affected by the activation and development of overlying rock fractures caused by repeated mining, it is easy to penetrate the aquiclude and lead to its instability, resulting in the loss of groundwater resources. The stability of aquiclude is an important prerequisite for realizing water- preserved mining. Upward fracture development height and downward fracture development depth are the important means to judge the stability of the aquiclude. Based on the working conditions of 4−2 and 5−2 coal seams in Hongliulin Coal Mine, the research was carried out in combination with numerical simulation experiments. The aquiclude failure characteristics of fracture development law under single coal seam mining and repeated mining are studied. The results show that the upper and lower fractures are not connected during the mining of single coal seam in 4−2 coal seam, and the aquiclude can maintain stability; during the repeated mining of 5−2 coal seam, the upper and lower fractures are penetrated and the aquiclude is unstable. Therefore, measures such as high-limiting mining and stratified mining should be taken in order to realize the water-retaining mining in this area.

     

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