综放开采覆岩离层形成机理
Formation mechanism of overburden bed separation in fully mechanized top-coal caving
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摘要: 以济宁二号煤矿采空区疏放水异常为例,基于组合梁原理得到离层发育层位判别公式对工作面离层发育位置进行预计,利用离散元软件UDEC对工作面离层动态发育过程及分布规律进行模拟,通过三维地震对离层发育层位及分布范围进行探测。结果表明,工作面达到充分采动后,最大离层约发育于顶板60 m的泥岩与上部厚层中细砂岩之间。依据薄板弹性理论,通过计算离层上下位岩层板的挠度差来预计离层体积,可作为采场顶板可发育离层最大总体积。Abstract: Taking the anomaly of dredging and draining water in the Jining No.2 coalmine as an example, this study predicts the development position of bed separation in the discriminant formula based on the composed rock beam theory, simulates the dynamic development process and distribution regularity of bed separation using discrete element software UDEC, and probe the position and spread of bed separation through 3D seismic.The result shows that the maximum bed separation developed in the larger gap between mudstone and middle-fine sandstone after the working face completed, the distance between the gap and coal seam is 60 m approximately.Based on the elastic thin plate theory, the study predicts the volume of bed separation by calculating the difference of deflection between upper and down rock plate.The predictive value can be used as the maximum total volume of bed separation developed in seam roof.