成达万高速铁路铜锣山隧道煤矿采空区勘察及评价

Survey and Evaluation of Coal Mine Goaf in Tongluoshan Tunnel of Chengdu-Dazhou-Wanzhou High-speed Railway

新建成都至达州至万州高速铁路铜锣山隧道横穿川东平行岭区的铜锣山背斜构造,三叠系须家河组含煤地层出露于狭长的条形山脉两翼,可采薄煤层较多,且开采历史悠久,形成“条带状密集连片、多层交错分布”的煤矿采空区。由于煤矿采空区变形影响范围大,持续时间长,对沉降影响敏感的高速铁路无砟轨道影响极大,因此确定采空区的影响范围,评价其对隧道工程的影响成为研究重点。通过采用调查走访、井下测量、物探及钻探验证的综合勘察方法,查明采空区分布边界及高程,通过相关规范及同类地层地表观测数据综合确定岩移参数,再结合预留维护带宽度确定采空区影响范围。研究结果表明,铜锣山隧道位于采空区影响范围外,采空区对铜锣山隧道基本无影响。

The newly-built Tongluoshan Tunnel of the Chengdu-Dazhou-Wanzhou High-speed Railway crosses the Tongluoshan anticline structure in the parallel ridge area in eastern Sichuan.There are many coal seams and a long history of mining,forming a coal mine goaf with“strip-like dense contiguous slices and multi-layer staggered distribution”.The large range and long duration of the deformation of the goaf in coal mines has influences on the ballastless track of the high-speed railway,which is sensitive to the subgrade settlement.Therefore,the determination of the influence range of the goaf and the evaluation in terms of its impact on tunnel engineering is the focus of research.Through methods including survey visit,downhole measurement,geophysical prospecting and drilling verification,the distribution boundary and elevation of gobs were found out,and the rock movement parameters were comprehensively determined through relevant specifications and surface observation data of similar strata.The scope of influence of the goaf was determined in combination with the width of the reserved maintenance zone.The research results show that,the Tongluoshan Tunnel is located outside the influence range of the goaf,and the goaf has basically no influence on the Tongluoshan tunnel.