煤巷倾斜层状顶板变形失稳机理及支护技术

Deformation and Stability Lost Mechanism and Support Technology of Inclined Layer Roof in Seam Gateway

针对鹤壁矿区二1煤层回采巷道顶板变形严重支护困难,从倾斜岩层非对称作用、水平构造应力、煤帮软弱失稳、底鼓塑性流动诱发等方面分析揭示了顶板失稳力学机理。采用高预拉力、高刚度护表构件控制围岩浅部离层,利用围岩深部自承能力;锚索减跨强力悬吊,帮角弱化区补强支护整体促稳等支护对策,并提出了预拉力锚网索梁联合支护技术参数。结果表明:掘进期,新支护方案下的巷道顶板最大下沉量44 mm,降低75%;两帮移近量最大77 mm,减小60%;回采期,顶板最终下沉量138 mm,两帮移近量为179 mm,巷道支护状况有了明显改观。

According to the serious deformation and difficult support of the mining gateway roof in No.Two1 seam of Hebi Mining Area,from the asymmetric role of the inclined rock strata,horizontal structure stress,soft and weak stability lost coal wall of the gateway,plasticity flow induction of the floor heave and others,the paper analyzed and revealed the stability lost mechanics mechanism of the roof.The high pre-tensile strength,high rigid surface protective structure was applied to control the separation of the surrounding rock in shallow depth and the self bearing capacity of the surrounding rock should be utilized.The support countermeasures applied would be including the anchor to reduce the powerful suspended force of the span,the reinforced support and the integrated stability promotion of the side wall and corner zone,and others.The paper provided the parameters of the pre-tensile bolt/steel mesh/anchor combined support technology.The results showed that with the application of the new support plan,during the gateway driving period,the max convergence value of the gateway roof was 44 mm and was reduced by 75%.The max convergence value of the two side walls was 77 mm and was reduced by 60%.During the mining period of the coal mining face,the final convergence value of the gateway roof was 138 mm and convergence value of the two side walls was 179 mm.The support condition of the gateway was obviously improved.