火成岩侵蚀复合顶板煤巷支护对策研究

The Supporting Measures of Roof Coal Roadway of Deep Igneous Rock Erosion

杨庄煤矿45210工作面埋深大,顶板为复合顶板,受火成岩侵蚀,易发生突然冒顶等灾害。笔者采用数值模拟和现场观测分析方法,认为该巷道变形破坏机制为:因火成岩侵袭复合顶板倾斜煤巷,顶板煤岩层粘聚力和抗拉强度降低;巷道开挖卸荷后,在竖向应力作用下,顶板受拉破坏严重,顶板下沉量增加,引起煤帮受拉破坏,两帮移近量增加;集中应力区由巷道围岩表面向围岩深部不断转移,围岩塑性区由巷道表面向深处逐渐扩张,最终导致巷道的变形和破坏;提出了"强顶、固帮"的支护对策。现场试验表明,与原设计方案相比,新设计方案可有效控制巷道围岩变形,降低巷道变形量达50%以上,取得了良好的支护效果。

The 45210 working face of Yang Zhuang Mine has a large burial depth,compound roof,and been eroded by igneous rock,which easily results in catastrophe like roof collapse. In this paper,by using the way of numerical simulation and field observation,the deformation and failure mechanism of roadway are concluded： because the inclined coal mine is eroded by igneous rock,which results in reduction in cohesion and tensile strength between coal layer and rock layer; the tensile failure of the roadway roof is severe and the roof subsidence increases under the vertical stress after the roadway is excavated,which leads to the tensile failure of coal walls and further increases the convergence of two walls; the area of stress concentration and the plastic zone respectively expanded from the surface to the deep of surrounding rocks,which eventually gives rise to the deformation and failure of roadway under this engineering geologic condition. According to the deformation and failure mechanism of roadway,the supporting design of＂roof strengthened,walls reinforced＂is proposed. In order to test the effect of the new supporting design,a observation plan is made according to the concrete execution condition. The result of observation shows that the new design can effectively control the deformation of the surrounding rock and reduce the deformation of roadway amounts to more than 50 percent,which attains better supporting effect under the new supporting scheme.