渐变大断面地铁隧道二衬施工技术

Construction Technology of Secondary Lining of Metro Tunnel with Gradual Change and Large Section

以石家庄地铁某暗挖大断面隧道为例,介绍了将隧道全断面分为仰拱、边墙、拱部3部分分步拆除局部临时支护,自下而上充分利用未拆除的临时支护的支撑作用,采用满堂脚手架+拱墙架+可调钢模板组成的模架体系来完成不同类型断面的二次衬砌施工技术,供类似工程施工参考。

This article takes an undercut large-section tunnel in Shijiazhuang Metro as an example. It introduces the step-by-step demolition of local temporary supports that divide the full section of the tunnel into three parts :inverted arch,side wall,and arch.For the supporting role of temporary support,a formwork system consisting of full-floor scaffolding,arch wall frame and adjustable steel formwork is used to complete the secondary lining construction technology of different types of sections,which can be used as a reference for construction of similar projects.