石板山隧道斜井与正洞交叉段施工方法与技术

Construction Methods for the Construction at the Incline-shaft-Tunnel-intercrossed Section

根据石板山隧道两斜井与正洞相交处的实际地质情况,施工时在Ⅲ级围岩胡雷斜井交点处采用了中导洞爬坡扩挖到正洞,然后反向挑顶、钢拱架及锚杆支护加固等措施;在Ⅳ级围岩的胡仁斜井交点处采用两台阶变三台阶的扩顶施工,详述了相应的施工工艺。实践证明,两种挑顶施工方法切实可行,安全、快速进入到隧道正洞施工,为类似工程提供借鉴。

According to the actual geological conditions of the Shibanshan Tunnel, which is located at an incline-shaft-tunnel-intercrossed section,the INF climbing expansion digging is performed up into the tunnel at the intersection of the Hu Lei Incline shaft of grade-Ⅲ surrounding rock, followed by the inverted top-digging, with steel gantry and anchor supports adopted to strengthen the tunnel. At the intersection of the Hu Ren incline shaft of grade-IV surrounding rock, the two-step digging method is changed to the three-step digging method for the top digging construction. The corresponding construction techniques used in the construction are described in detail in the paper. Practice has proved that the top-digging construction methods are practicable, safe and fast in entering the hole proper for tunnel construction. The project may serve as a useful reference for other similar projects in the future.