大直径盾构隧道下穿南水北调中线总干渠设计研究

以新郑机场至郑州南站城际铁路盾构隧道下穿南水北调中线总干渠为例,研究下穿段盾构隧道结构、沉降、防水、加强措施、监测方案等设计关键问题,以指导盾构下穿施工。通过模拟不同工况下盾构隧道结构受力,计算确定盾构管片的配筋方案;通过三维数值模拟分析盾构下穿施工对南水北调中线总干渠的影响。考虑南水北调工程的重要性,设计中采取一系列确保总干渠安全的措施。盾构隧道安全、顺利穿越南水北调中线总干渠,各项监测数据及指标满足预期,表明本文提出设计措施有效地控制了盾构下穿施工对总干渠的影响,确保了盾构施工安全和南水北调中线总干渠安全。

Study on Design of Large Diameter Shield Tunnel Passing Underneath The Middle-Route Trunk Canal of South-to-North Water Diversion Project

The intercity railway from Zhengzhou Xinzheng international airport to Zhengzhou South railway station passes underneath the middle-route trunk canal of South-to-North Water Diversion Project by means of a shield tunnel. Taking this project as an example, this paper studies some key issues involved in the design of large-diameter shield tunnel design, including structure, settlement, waterproof, strengthening measures and monitoring plan so as to guide the construction of shield underpass. The steel reinforcement scheme of shield segment is determined by simulating the stress of shield tunnel structure under different working conditions. Also, the influence of shield tunneling construction on the trunk canal is analyzed by three-dimensional numerical simulation. Considering the importance of the South-to-North Water Diversion Project, a series of measures are taken in the design to ensure the safety of the trunk canal. The shield tunnel successfully crosses underneath the middle-route trunk canal of South-to-North Water Diversion Project and the monitoring data and indexes meet the expectation, indicating that the design measures in this paper effectively controls the negative influence of the shield tunneling construction on the canal, and ensures the safety of the shield tunneling construction and the canal.