地铁超高暗挖结构二衬特殊支架法施工技术

Construction Technology of Special Second-lining Bracket Method for Subway Undercutting Structure

暗挖施工的地铁工程中经常会遇到一些超高的结构,如地铁车站的风道、施工横通道等,这些结构一般高度均超过10m,采用CRD法分多层开挖支护,其二衬施工的常规做法是由下至上,分层拆除临时支撑,分层施做二衬,并加设多层临时支撑,以保证结构的安全.这种施工方法需要的支架数量多,搭设的高度大,施工周期长,安装支架和模板的风险高,一旦出现意外,应急抢险难度大.如何能在不影响施工速度的情况下,提高施工的安全性,增加材料的周转效率,减少模板支架及临时支撑的用量,以达到保证安全,降低成本的目的.本文以长春地铁自南区间盾构通道施工为例,很好的解决了此问题.

There are some ultra-high structures in the subway construction projects,such as the air channel in the subway station,construction cross channel,etc.These structures are generally over 10 meters highly,which used CRD method to excavate the support.The second lining method is usually used to remove the temporary support from the bottom to the top,and to make the second lining separately.Furthermore,multi-temporary support will be set to ensure the safety of the structure.With more brackets,erection height,long construction period,high risk of mounting bracket and templates,it is more difficult to rescue if an accident occurs.In order to ensure the safety and reduce the cost,the paper aims to improve the safety of construction,increase the turnover efficiency of materials,reduce the amount of template bracket and temporary supports without the influence of the construction process.A good solution to the problem is given by the example of channel construction in the south section of Changchun subway.