厚煤层大断面托顶煤巷道围岩稳定控制研究

Study on stability and control of surrounding rock of roadway with large section in thick coal seam

为解决龙泉煤矿4#煤层大断面托顶煤巷道稳定性问题,以龙泉煤矿4203工作面回风巷为研究对象,采用理论分析、数值模拟及现场实测相结合的方法对巷道稳定性进行研究;首先建立了巷道岩层稳定性力学分析模型,并推导了顶煤破碎位置计算公式,确定了影响顶煤破坏的主要因素;其次采用UDEC-Trigon模型对不同顶煤厚度下巷道的应力、塑性区及围岩位移量进行了分析。结果表明:巷道顶板发生剪切破坏与岩石内摩擦角及岩块(面)之间的摩擦角有关,且破坏位置在巷道两帮肩角位置。通过对比不同顶煤厚度下支护方案的支护效果,提出了4203工作面回风巷高预应力、高强度锚杆索及时支护巷道的围岩综合控制技术;优化后的支护方案在现场进行了应用,实测得出顶底板最大变形量为104 mm,两帮最大变形量为86 mm,实施效果得到明显提升。

In order to solve the stability problem of large section top coal roadway in No.4 coal seam of Longquan Coal Mine,taking the return airway of 4203 working face of Longquan Coal Mine as the research object,the roadway stability is studied by the combination of theoretical analysis,numerical simulation and field measurement.Firstly,the mechanical analysis model of roadway rock stability is established,the calculation formula of top coal crushing position is deduced,and the main factors affecting top coal failure are determined.Secondly,UDEC-Trigon model is used to analyze the stress,plastic zone and surrounding rock displacement of roadway under different top coal thickness.The results show that the shear failure of roadway roof is related to the internal friction angle of rock and the friction angle between rock blocks(surfaces),and the failure position is at the shoulder angle of two sides of roadway.By comparing the supporting effects of supporting schemes under different top coal thickness,the comprehensive control technology of surrounding rock for timely supporting roadways with high pre-stress and high strength bolt and cable in return airway of 4203 working face was proposed.The optimized support scheme was applied in the field,and the measured maximum deformation of roof and floor was 104 mm,and the maximum deformation of two sides was 86mm,and the implementation effect was significantly improved.