高寒膨胀土地区单线铁路隧道深埋中心水沟的施工方法

Construction Method of Deep-buried Central Ditch in Single Line Railway Tunnel in High Cold and Expansive Soil Areas

高寒、膨胀土地区单线铁路隧道深埋中心水沟施工空间小、基坑深、坑壁渗水严重时坑壁易失稳滑塌,施工难度极大。北黑铁路升级改造工程卧牛隧道在深埋中心水沟开挖过程中发生严重渗水,采用传统喷锚网施工方法不能保证坑壁的稳定性且严重威胁作业人员安全。为顺利开展施工,研究探索出一种在洞外预制支护构件的方法,将支护刚度提前形成,在基坑开挖后直接吊装就位。通过对传统工艺进行革新,成功解决了施工难题,降低了人员在深埋中心水沟施工时的作业时间,降低了安全风险。

In the construction of the single line railway tunnel deep buried in the central trench in the cold and expansive land area,the construction space is narrow,the foundation pit is deep,and the pit wall is prone to unstable and slippery collapse,and the construction is extremely difficult.The Woniu Tunnel of the Bei'an to Heihe Railway Upgrading and Reconstruction Project has serious seepage during the excavation of the deep buried central ditch,and the traditional spray anchor net construction method cannot ensure the stability of the pit wall and seriously threatens the safety of operators.In order to carry out the construction smoothly,a method of prefabricating supporting members outside the cave was researched and explored,and the supporting stiffness was formed in advance and directly hoisted into place after the excavation of the foundation pit.It makes a bold innovation in the traditional process,successfully solves the construction problem,and reduces the working time of personnel during the construction of the deep buried central trench and reduces the safety risk.