偏压滑坡体连拱-分岔隧道进洞施工技术研究

Study on Construction Technology of Double-Arch and Bifurcated Tunnel Entering the Hole in Biased Landslide

以广东省内某连拱-分岔隧道为例,隧道在临河陡崖特殊环境条件下进洞,且进口存在偏压、右线存在崩滑体,地形、地质条件复杂,进洞难度大等。通过对偏压、滑坡体等采取抗滑桩+锚索格梁的上边坡防护技术,对露拱部分采用大边墙支护施工技术,对浅埋段落采用护面墙防护施工技术,对直墙连拱隧道进洞段采取“三导洞开挖,先施工中间墙,后施工两侧洞”的进洞施工技术,成功克服偏压滑坡体连拱-分岔隧道进洞施工难题,相关技术经验可为类拟工程设计、施工提供参考。

This paper takes a double-arch and bifurcated tunnel in Guangdong Province as an example.The double-arch and bifurcated tunnel enters the hole under the special environmental conditions which are steep cliffs near the river,and there is bias at the inlet,collapse and slide mass on the right line,the terrain and geological conditions are complex,making it difficult to enter the tunnel.Anti-slide pile and anchor cable lattice beam is adopted to protect the upper slope against bias and landslide.The large side wall supporting construction technology is adopted for the exposed arch part.For shallow buried sections,protective construction technology of face wall is adopted.The tunnel-entering construction technology adopted for the straight wall and double-arch tunnel is three guide tunnel excavation,construction of the middle wall first,then construction of the two sides of the tunnel.This construction technique successfully overcomes the construction problem of multi-arch bifurcation tunnel in biased landslide.Its relevant technical experience can provide reference for the design and construction of similar projects.