浅埋煤层覆岩破坏规律及裂隙发育特征是影响矿井涌水有关系，尤其在地表沟谷区，由于剥蚀作用使煤层埋深减小，为了研究清楚浅埋煤层过沟开采时，上覆岩层的扰动破坏规律与裂隙发育特征，以榆神矿区张家峁煤矿14213工作面的过沟段为研究对象，通过相似材料物理模拟与数值模拟的方法，对覆岩的破坏规律及裂隙发育特征进行了研究。结果表明，煤层开采过程中，顶板覆岩会伴随产生层间离层与切穿岩层的垂向裂隙，回采至60 m时，煤层顶板悬露面积达到极限发生垮落，原有层间离层伴随垮落消失，新出现的层间离层继续向上发展，离层空间与垂向裂隙交替发育，回采至105 m时，垂向裂隙导通至地表，离层结构完全破坏，岩层发生整体下沉。裂缝的动态发育规律是：斜坡裂缝的宽度随着开挖的进行由小变大并趋于稳定，坡脚裂缝的宽度则是由小变大、再变小至闭合，沟底裂缝的宽度由小变大再变小的趋势。地表裂缝的这种演化规律主要与地形和地表应力状态有关。坡肩和斜坡上部，采动裂缝形成后受斜坡拉应力的影响而宽度增大；坡脚采动裂缝形成后受坡脚压应力的影响而宽度变小甚至闭合；沟底采动裂缝形成后受压应力和坡段岩块压实调整宽度变小。

The overburden failure law and fracture development characteristics of shallow coal seam are the main factors affecting the mine water inflow and ventilation，especially in the surface gully area，because of the denudation，the coal seam buried depth is further reduced. In order to study the disturbance failure law and fracture development characteristics of overlying strata when mining through trench in shallow coal seam，taking the trench section of No.14213 working face of Zhangjiamao Coal Mine in Yushen Mining Area as the research object，the failure law and fracture development characteristics of overlying strata are studied by means of physical simulation and numerical simulation of similar materials. The results show that in the process of coal mining，the roof overlying rock will produce vertical fractures of interlayer separation and cut through strata. When mining to 60 m,the roof hanging area of coal seam reaches the limit and collapses. The original interlayer separation disappears with collapses. The new interlayer separation continues to develop upward. The separation space and vertical fractures develop alternately. When mining to 105 m，the vertical fractures lead to the ground:the separation structure is completely damaged，and the rock stratum is sinking as a whole. The dynamic development law of the cracks is:the width of the slope cracks increases and tends to be stable with the excavation; the width of the slope foot cracks changes from small to large，then to close，and the width of the bottom cracks changes from small to large and then to small. The evolution law of surface fractures is mainly related to the topography and surface stress state. In the shoulder and upper part of the slope，the width affected by the tensile stress of the slope increases after the formation of the mining fracture; the width affected by the compressive stress of the slope toe decreases or even closes after the formation of the mining fracture at the slope toe; the width of the compressive stress and the compaction adjustment of the slope rock block decreases after the formation of the mining fracture at the ditch bottom. The research results have important reference value for the crack control and water damage control of shallow coal mining channel.

0 引言

1 工作面概况

2 覆岩破坏特征相似材料模拟

   2.1 相似材料模拟模型的建立

   2.2 覆岩破坏过程

   2.3 垮落带和断裂带高度发育规律

   2.4 地表裂缝发育规律

3 地表裂缝数值模拟分析

4 结论