大直径盾构空推通过矿山法隧道段的施工技术研究

Research on Construction Technology of Large Diameter Shield Advancing Mined Tunnel without Load

针对东南沿海地区某城际轨道交通大直径(8.8 m)盾构空推通过矿山法隧道段的施工项目,对盾构进洞前、空推及出洞期间的施工控制措施及变形控制技术进行了研究。结果表明:施工完成后整个空推通过的矿山法隧道段的管片拼装在左线水平和高程的最大偏差分别为11 mm、9.6 mm;在右线水平和高程的最大偏差分别为12 mm、10 mm;左、右线隧道拱顶位置的最大沉降值分别为2.42 mm、4.61 mm。管片拼装偏差及隧道的变形均满足现有规范的控制要求。此施工工艺保证了大直径盾构机快速、安全和高质量地通过矿山法施工的硬岩区段,既节省了工期,又保证了质量和施工安全。

Taking the construction project of a large diameter(8.8 meter)shield advancing through an existing tunnel constructed by mining method in the southeast coastal area as subject,the construction control measures and deformation control technology during periods of before entering the tunnel,advancing without load and exiting the tunnel are studied.Results show that after construction,the segment installation of the mined tunnel that is crossed without load has maximum deviation of 11 mm and 9.6 mm in left line level and elevation respectively.The maximum deviation is 12 mm and 10 mm in right line level and elevation respectively.The maximum settlement amount of the tunnel roof is 2.42 mm in the left line and is 4.61 mm in the right line.The segment installation deviation and tunnel settlement both meet the control standards of the specification,and it is guaranteed that large diameter shield machine can pass through the hard rock section quickly,safely,with high quality.Not only the time until completion is saved,but also can it ensure quality and safety of tunnel construction.