溶洞性顶板回撤通道三级支护技术研究

Study on Three-level Support Technology of Karst Cave Roof Retreat Channel

对围岩破坏机理认识不清以及支护方案不当是导致溶洞性顶板巷道围岩变形量过大甚至冒顶的主要原因。以永聚煤业10102工作面回撤通道为背景,采用现场调研、理论分析与数值模拟等方法研究了溶洞性顶板巷道围岩的破坏机理及其支护优化方法。研究结果表明:10102工作面回撤通道顶板2~5 m内溶洞发育且受奥灰水侵蚀导致软弱夹层不断扩展,原支护参数较弱且支护方式不合理导致溶洞性顶板巷道冒顶;优化后的中空注浆锚索、高强锚杆、单体柱+π形钢梁的三级支护方案可有效降低溶洞性顶板巷道围岩的破坏程度和破坏范围,三级支护方案现场应用效果良好。

Unclear understanding of the failure mechanism of surrounding rock and improper support scheme are the main reasons that lead to excessive deformation of surrounding rock of karst cave roof roadway and even roof fall. With the withdrawal channel of 10102 working face of Yongju Coal Industry as the background, the failure mechanism of surrounding rock of karst cave roof roadway and its support optimization method were studied by field investigation, theoretical analysis and numerical simulation. The research results show that within 2 ~5 m of the roof of the retreat channel of 10102 working face, karst caves are developed and the weak interlayer is continuously expanded due to the erosion of Ordovician lime water. The weak original support parameters and unreasonable support methods lead to roof fall of the tunnel with karst cave roof. The optimized three-level support scheme of hollow grouting anchor cable, high-strength anchor rod, single column +π-shaped steel beam can effectively reduce the damage degree and damage scope of the surrounding rock of the cave roof roadway, and the three-level support scheme has a good effect on site application.