浅埋厚煤层回采巷道围岩破坏分析及支护优化

Failure analysis of the rock strata surrounding the roadways in the shallow thick seam coalmine and its supporting optimization

为解决神东矿区浅埋厚煤层回采巷道围岩变形量大、巷道维护效果不佳等问题,以神东矿区某矿105工作面胶运顺槽为工程实例,综合利用理论分析、数值模拟和现场实测方法,对巷道围岩破坏机制和围岩应力状态进行分析并对巷道支护方案进行优化。结果表明：巷道支护的主要对象是巷道塑性区内圈松散破碎煤岩体;巷道顶板、副帮、正帮松动破坏范围分别为3.42 m、1.51 m、1.36 m;巷道锚杆锚固段未全部处于深部稳定煤岩体中,锚杆锚固能力未得到充分发挥,是导致巷道围岩变形量大、锚固失效的根本原因。基于巷道围岩松动圈实测和数值分析结果,对巷道支护方案进行优化,现场应用表明,巷道支护方案优化后,锚杆支护作用得到充分发挥,巷道表面位移降幅明显,巷道维护效果得到明显改善。

To solve the severe deformation and poor support effect of the shallow thick coal seam in Shendong mining area, the paper would like to take the haulage roadway of Panel 105 in a coal mine in Shendong mining area as the engineering background sample to establish a roadway surrounding rock loosen broken structural model and a bolt support numerical analysis model based on the actual geological data, and try to measure the haulage roadway surrounding rock loosen broken circle of the aforementioned panel. In the paper, we have analyzed the roadway surrounding rock failure mechanism and the stress distribution through an optimized bolt-supporting plan on the comprehensive methods of the theoretical analysis, numerical simulation and the field application. The results of our analysis show that the inner ring of the roadway plastic zone is the loose broken zone and the coal and rock mass in the loose broken zone as the main support research object. As a result of calculation, the loose broken scope of the roadway roof, the coal wall beside pillar and the coal wall beside the coal seam body have all been worked out at about 3.42 m, 1.51 m and 1.36 m, respectively. Based on the loosen bro- ken circle in-situ measurement and the surrounding rock failure numerical simulation, the anchoring area of the bolt is not all based in the stable rock and coal mass, due to the fact that the anchorage ability of the bolt is not fully played and it is the primary reason and ration that may coconut for the large deformation of the surrounding rock and the failure of bolt anchorage ability. On the other hand, it is realistic to optimize the bolt support plan based on the status-in-situ measurement of the surrounding rock loose circle and numerical simulation analysis results with the proper monitoring and control of the bolt anchoring force and roadway surface displacement. Furthermore, the field application of the model shows that the bolt anchorage force can be put into effective application whereas the roadway surface displacement can also be reduced obviously by improving the support effect. Thus, it can be seen that the given study can be expected to provide a basis for roadway surrounding rock control and design the supporting plan in Shendong mining area and other mines with similar conditions.