为研究综采工作面采动覆岩压实区演化综合因素影响效应，运用物理相似模拟试验及理论分析相结合的研究方法，开展不同采高（2m<4m<6m）、不同推进速度（3m/d<5m/d<7m/d）以及不同煤层倾角（0°<15°<30°）条件下的采动覆岩压实区裂隙演化规律的研究，得到了压实整体形态随工作面采高、推进速度以及煤层倾角变化的演化规律。结果表明：采空区覆岩“三带”高度随着工作面采高的增大、推进速度的减小以及煤层倾角的增大呈线性增大趋势。采空区上覆岩层离煤层顶板越远，其贯通度数值越小，并在达到一定高度后，出现迅速减小的现象。受更高层位岩层的挤压以及两侧煤壁的支撑作用，覆岩离层率呈现两侧高于中部的“马鞍形”。构建出以覆岩贯通度突减、覆岩离层率突增以及裂隙带发育高度为依据的综采工作面覆岩压实区边界判定准则，得到了不同开采条件下覆岩压实区整体发育形态，进而发现工作面采高对压实区影响主要表现在高度方面，煤层倾角对压实区宽度和对称度的影响较大，推进速度对压实区的高度与宽度都有较为明显的影响。基于采动裂隙椭抛带理论，结合物理相似模拟试验结果，构建了多因素影响下的采动裂隙椭抛带压实区演化综合效应模型，并结合工程实践，有效提高了现场瓦斯治理效果，保证了工作面的安全回采。

In this work, the physical similarity simulation test and theoretical analysis were used to study the compacted area of fully mechanized mining face under multiple factors. These factors include different mining heights (2，4，6 m), different advancing speeds (3 m/d,5 m/d,7 m/d), and different dip angles of coal seam (0°,15°,30°). The evolution law of the shape of compacted area with the change of the above factors was obtained. The results showed that the height of "three zones" in goaf increased linearly with the increase of mining height, the decrease of advancing speed and the increase of dip angle of coal seam. The farther away from the roof of coal seam, the smaller the permeability of the overlying strata was. The penetration decreased rapidly after reaching a certain height. The separation rate of overlying strata was squeezed by the higher strata and supported by the coal wall, showing a saddle shape on both sides higher than that in the middle. Based on the sudden decrease of strata permeability, the sudden increase of strata separation rate and the development height of fracture zone, a criterion for determining the boundary of overburden compacted area was constructed. The overall development morphology of compacted area under different conditions was obtained, and it was found that the mining height has a great influence on the height of compacted zone, the dip angle of coal seam has a great influence on the width and symmetry of compacted area, and the influence of advancing speed on the height and width of compacted area is relatively balanced. Finally, based on the theory of mining fissure elliptic paraboloid zone, combined with the experimental results, the mathematical equation of the compacted area of the mining fracture elliptical belt affected by the above factors was established. The engineering practice has proved that it effectively improves the effect of field gas control and ensures the safe mining of working face.

0 引言

1 试验

   1.1 试验原型

   1.2 试验过程

2 试验结果

   2.1 覆岩“三带”高度变化规律

   2.2 覆岩贯通度变化规律

   2.3 覆岩离层率变化规律

3 讨论

   3.1 覆岩压实区边界判定准则

   3.2 多因素下覆岩压实区形态特征演化规律

   3.3 采动裂隙椭抛带压实区演化综合效应模型

4 工程实践

   4.1 高位钻孔布置

   4.2 高位钻孔抽采效果

5 结论