采场上覆岩层离层位移确定方法及其应用

Determination Method of Separated Layer Displacement in Overburden Strata Above Coal Mining Face and Application

为了快速而准确的确定煤层回采过程中采场上覆岩层的离层位移,指导地面瓦斯抽采钻井防护工程的开展,结合地表沉降规律和组合关键层理论分析了采动影响下采场上覆岩层离层位移的产生原因,构建了一种计算采场上覆岩层离层位移量的经验计算方法,并通过数值模拟对计算方法进行了验证,同时将该方法应用到了晋城煤业集团成庄煤矿地面瓦斯抽采钻井工程试验中。结果表明:采场上覆岩层离层位移的大小由离层界面上下两组合关键层的沉降位移量之差决定,其沿采场倾向方向的分布规律,呈现采场中间最高、由采场中间向两端逐渐减小的变化规律,地面钻井的布井宜选择在采场沉降拐点与采场边界之间的区域。

In order to quickly and accurately determine the separated layer displacement of the overburden strata above the coal mining face during the seam mining process and to guide the implementation of the surface gas drainage borehole drilling protection project,the combination of the surface subsidence law and the combined key layer theory were applied to analyze the cause of the separated layer displacement of the overburden strata above the coal mining face under the mining influences and to establish an experience calculation method to calculate the separated layer displacement of the overburden strata above the coal mining face.With the numerical simulation,the calculation method was verified and was applied to the trial on the surface gas drainage borehole drilling project of Chengzhuang Mine,Jincheng Coal Mining Group.The results showed that the separated layer displacement size of the overburden strata above the coal mining face would be dependent on the subsidence displacement differences between the top and low combined key layer of the separated layer interface.The distribution law of the separated layer displacement along the inclination direction of the coal mining face would have a high peak in the middle of the coal mining face and would have a variation law getting small from the middle of the coal mining face to the ends of the coal mining face.The borehole layout of the surface borehole drilling would be suitable to be selected in the area between the subsidence turning point of the coal mining face and the coal mining face boundary.