采用矿山法构筑区间盾构隧道渡线段的方案探讨

针对北京地区地质条件，提出了在区间盾构隧道之间采用矿山法构筑渡线隧道的方案，即先在最大开挖断面处拆除管片，沿横向扩挖出一条施工通道；然后在施工横通道侧壁开口，从大断面向小断面进行渡线隧道的断面渐变段、双联拱段和分离单洞的施工，从而在两条区间盾构隧道之间采用矿山法完成渡线隧道的施工；最后，应用FLAC数值计算软件，探讨了管片拆除及隧道断面扩挖引起的地表沉降和塑性区分布范围。研究结果表明，针对北京地区的地质条件，提出的在区间盾构隧道之间采用矿山法构筑渡线隧道的方案具有工程适用性。

Probe into construction method for connecting tunnel between two shield tunnels

A mining construction method being aimed at Beijing region geological condition is brought forward for connecting tunnels based on two shield tunnels. Firstly, part of the shield segments in this maximal connecting tunnel section is taken off and a construction traverse channel is built. Secondly, each part of the connecting tunnel is constructed by regarding the traverse channel as a construction working face. Finally, A numerical simulation with FLAC software is adopted to probe surface subsidence and stratum plastic region distribution after the shield segments being disassembled and the tunnel cross-section being widened. The result indicates that the connecting tunnel between two shield tunnels can be constructed by using mining method; and the construction method is doable to Beijing region geological condition.