特厚煤层沿顶巷道抗剪锚管索帮角控制技术研究

Research on shear resistance and angle control of tube anchor cable inroof roadways of extra-thick coal seams

针对特厚煤层沿顶巷道帮角围岩破碎外挤、锚索自由段受不均匀组合荷载作用导致的端部上翘和帮部变形较大等问题,以同忻矿8204巷道为研究对象,通过现场调研、拉剪试验、FLAC3D数值模拟和现场工业性试验等方法,并利用研发的抗剪锚管索支护结构进行特厚煤层沿顶巷道抗剪锚管索帮角控制技术研究。首先开展拉剪试验,测试锚索组成抗剪锚管索结构前后的承载能力;其次在不考虑原岩应力影响的条件下,通过对巷道围岩内部支护应力场的分布情况,查找原支护方案帮部支护效果较差的原因;最后结合强帮强角支护理念,提出抗剪锚管索帮角控制技术及支护优化方案,利用数值模拟方法险证该优化方案的支护效果,并在现场进行长为300 m的工业性试验。现场监测数据表明,应用所研抗剪锚管索帮角控制技术后,特厚煤层沿顶巷道围岩变形得到了有效控制。

Addressing issues such as extrusion and fragmentation of the surrounding rock at the top corner,end warping of the free section of the anchor cable under uneven combined load,and significant deformation of both sides in roadways along the roofs of extra-thick coal seams,this study focused on the 8204 roadway of the Tongxin mine.It employed field investigation,tensile and shear tests,FLAC3D numerical simulations and field industrial experiments.The research also involved the development and application of the shear-resistant anchor cable with C-shaped tube(ACC)for controlling sidewall and corner stability in such road‐ways.Initially,tensile and shear tests were conducted to assess the bearing capacity of ACC;Subsequently,an analysis of the stress distribution within the roadway’s surrounding rock was carried out without considering the influence of the original rock stress;This analysis aimed to identify the reasons for the poor support effect of the original support scheme.Finally,in conjunction with the concept of reinforcing sidewalls and corners,this study proposed ACC sidewall and corner control technology and an optimized support scheme.Numerical simulations confirmed the effectiveness of the optimized scheme.A 300 m-long industrial experiment was conducted in the field,and the monitoring data showed that the deformation of the surrounding rock had been effectively controlled through the application of ACC sidewall and corner control technology.