双峰寨隧道施工难点应对技术分析

Technical Analysis of Shuangfengzhai Tunnel Construction Difficulties

摘要: 在双峰寨隧道施工过程中，部分施工区域存在围岩稳定性较差、纵向坡率大和洞内涌水等施工难题。基于施工过程中的难点，在隧道暗洞浅埋段和洞口分别采用超前大管棚配备超前注浆小导管和Vc型复合式衬砌；在纵向坡率较大地段采取了反坡排水的施工方案。测量结果表明：采用了反坡排水后，最终将排水累积量控制在了100 m³/h左右；依托于各难点处采用的施工方案，隧道洞口的监测沉降值约为47 mm，沉降值在接受范围内。

Abstract: During the construction of Shuangfengzhai Tunnel, there are construction problems in some construction areas, such as poor stability of surrounding rock, large longitudinal slope rate and water inrush in the cave. Based on the difficulties in the construction process, the shallowly buried section of the tunnel and the entrance of the tunnel are equipped with advanced grouting small conduit and Vc-type composite lining. In the section with a large longitudinal slope, a construction plan of reverse slope drainage was adopted. The measurement results show that after using reverse slope drainage, the cumulative amount of drainage is finally controlled at about 100 m³/h. Relying on the construction scheme adopted at each difficult point, the monitoring settlement value of the tunnel entrance is about 47 mm, and the settlement value is within the acceptable range.