含夹矸泥岩煤层巷道外错滑移机理与支护对策

Study on Outward Sliding Mechanism of Roadway in Mudstone Interlayers Coal Seam and Support Method

为了揭示三道沟矿区含厚度20 cm泥岩夹矸的5-2号煤层巷道副帮外错变形机理,通过巷道围岩钻孔窥视、围岩变形观测和夹矸泥岩矿物成分X-衍射分析,测定出泥岩夹矸中蒙脱石含量达到55%,高岭石含量达到24%;探明了巷道顶板存在垂直裂隙,巷道副帮(煤柱帮)破坏区较大,巷道收敛变形主要由相邻工作面开采引起,巷道副帮出现较明显的外错式变形。通过数值计算分析,揭示了巷帮外错滑移破坏的机理是相邻工作面侧方支承压力导致煤柱顶板产生垂直裂隙并向相邻采空区水平移动,带动巷道副帮沿夹矸层滑移,形成外错变形。据此,提出了采用长锚杆加强副帮夹矸层上部煤体的支护对策,实践取得了成功。

In order to reveal the pillar rib outward sliding mechanism of entry in No. 5-2 coal seam with 20 cm mudstone interlayer in Sandaogou mining area,through borehole observation,convergence observation and mineral composition of X-ray diffraction analysis,it was determined that montmorillonite content was 55% and kaolinite content was 24% in the mudstone.It was found that there were vertical frac-tures in the roof,and pillar rib damage area was larger.The entry convergence deformation was mainly aroused by the adjacent face mining, and the outward sliding deformation was mainly occurred in the pillar rib.Based on the numerical analysis,the mechanism of pillar rib out-ward sliding was that the lateral abutment pressure aroused by the adjacent face mining and led to pillar roof vertical fracture and the hori-zontal movement to adjacent goaf,and pillar rib along mudstone interlayer sliding and outward sliding deformation.Based on the discovery, the support method of long anchor strengthen rib alone mudstone interlayer was put forward,and achieved successful application.