浅埋黄土区隧道套拱明洞暗挖施工技术

Undercutting construction of open tunnel with covered arch in shallow buried loess area

针对浅埋黄土区隧道地面条件复杂、明挖法施工难度大等问题,分析了明挖法和套拱明洞暗挖法两种施工方案的优缺点,确定采用套拱明洞暗挖法过浅埋黄土区。并从洞口防护排水、套拱暗挖施工、冒顶段明挖扣拱施工、管棚段三台阶临时仰拱法施工、二衬施工等方面研究了浅埋黄土隧道套拱明洞暗挖施工技术。结果表明,采取该施工技术,既确保了隧道的安全施工,又保护了周边原生态环境,同时降低了工程造价,取得了良好的经济和社会效益。

Aiming at the complex ground conditions and large difficulty for tunnel open - cut construction in shallow buried loess area, we analyzed the advantages and disadvantages of open -cut method and undercutting of open tunnel with covered arch, and the later method was selected to cross shallow buried loess area.The undercutting construction technology of open tunnel with covered arch in shallow buried loess area was studied, from the entrance fencing and drainage, covered arch undercutting, open - cut supporting arch in roof caving section, three bench temporary lateral bracing construction in pipe shed section, and secondary lining construction. The results showed that, favorable economic and social benefits were achieved using the proposed construction technology, which not only ensured the safety of tunnel construction, protected the surrounding ecological environment, but also reduced the project cost.