煤层群开采覆岩运移规律及“三带”高度确定

    Law of overburden movement in coal seam group mining and the determination of “three zones” height

    • 摘要: 为研究煤层群开采条件下覆岩移动规律及“三带”分布范围,基于神东布尔台煤矿42106工作面概况,采用相似模型物理实验方法模拟了2-2煤及4-2煤2层煤先后开采的覆岩移动变化特征,分别就覆岩垮落特征、应力变化、岩层下沉量3个方面进行了对比分析。结果表明:上煤层工作面开采结束后,覆岩破坏程度整体较低,应力峰值主要存在工作面超前影响区域,存在块体铰接等现象;下层煤开采后裂隙带与上层煤采空区沟通,导致复合煤层采空区的断裂带远大于上煤采后的断裂带,应力相比上煤层整体较大,且顶板下沉量显著增大,覆岩历经离层、离层增大,最终闭合3个阶段。通过观测点数据测量确定了42106工作面“三带”高度,并在现场进行钻孔监测,验证了相似物理模拟结果的合理性。

       

      Abstract: In order to study the law of overburden movement and the distribution range of “three zones” under the condition of coal seam group mining, based on the general situation of 42106 working face of Shendong Buertai Coal Mine, the physical experiment method of similar model is used to simulate the overburden movement characteristics of 2-2 coal and 4-2 coal successively, and the characteristics of overburden caving, stress change and strata subsidence are compared and analyzed respectively. The results show that after the mining of the upper coal seam face, the failure degree of the overlying rock is low as a whole, and the stress peak value mainly exists in the leading influence area of the working face, block hinge and so on. After the lower coal mining, the fracture zone communicates with the upper coal goaf, resulting in that the fracture zone of the goaf of the composite coal seam is much larger than that of the upper coal seam, the stress is larger than that of the upper coal seam as a whole, and the roof subsidence increases significantly. The overburden has gone through three stages of separation and separation increasing, and finally closed. The “three zones” height of 42106 working face is determined by the data measurement of observation points, and the borehole monitoring is carried out in the field to verify the rationality of similar physical simulation results.

       

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