复合煤层多组工作面开采条件下覆岩破坏规律研究

Overburden Failure Law under Mining Condition of Multi-face in Composite Coal Seam

为探究复合煤层覆岩运移与破坏规律,以陕西某矿为例,运用3DEC软件完整复现了垂直尺度的地质赋存环境,通过模拟复合煤层双组工作面下行开采过程,对覆岩破坏规律、导水裂隙带发育趋势、沟谷型地表变形特征进行分析。结果表明:下组煤开采时垮落带相较于裂隙带会更快达到稳定状态。裂隙带高度是上组煤层开采时的3.5倍,相较于上组煤裂隙带会更慢达到稳定状态,并会促进上组煤裂隙带的进一步扩展,导致沟谷型地表下沉区域均呈明显“条带状”分布特征,易使沟谷中心及凸出型沟谷一侧承受水害影响。

In order to explore the migration and failure law of the overburden of the composite coal seam,taking a mine in Shaanxi as an example,3DEC software is used to completely reproduce the vertical scale geological occurrence environment,and the overburden failure law,the development trend of waterconduction fracture zone and the deformation characteristics of valley-type surface are analyzed by simulating the downward mining process of the double working face of composite coal seam.The results show that the collapse zone of the lower group will reach a stable state faster than the fracture zone during mining.The height of the fracture zone is 3.5 times that of the upper group of coal seam mining,which will reach a stable state more slowly than that of the upper group of coal fracture zone,and will promote the further expansion of the upper group of coal fracture zone,resulting in obvious "band-like" distribution characteristics in the valley-type surface subsidence area,which is easy to make the center of the valley and the side of the protruding valley bear the influence of water damage.