深埋超特长输水隧洞TBM集群施工关键技术探析

北疆供水二期工程中的西二、喀—双、双—三隧洞总长516.19 km,设计采用18台TBM分段掘进,其中喀—双隧洞单洞长283.27 km,是目前世界在建最长的输水隧洞。深埋、超特长、TBM集群施工是该隧洞工程建设的显著特点,结合区域地质构造特征、工程地质条件和大量地质勘探成果,分析了存在的主要工程地质问题,提出了TBM结合钻爆法联合分段掘进的施工组织方案。并围绕深埋隧洞施工支洞及TBM进入通道型式的选择布局、超特长隧洞分段施工及TBM掘进方案优化设计、TBM集群施工及配套系统高效运行管理、地质灾害预测预报及风险防范控制、软岩变形控制及断裂破碎带安全掘进等工程建设中的重点、难点及关键技术问题,开展了分析讨论。可供TBM设计制造和长隧洞工程建设借鉴参考。

Key techniques for group construction of deep-buried and super-long water transfer tunnel by TBM

The Xi-Er, Kashi-Shuang and Shuang-San tunnels of the 2^nd stage water transfer project in the northern areas of Xinjiang Uygur Autonomous Region are totally 516.19 km in length, and they are designed to be constructed section by section using 18 TBMs. Among which, the Kashi-Shuang tunnel, with a single tunnel 283.27 km in length, is currently the longest water transfer one to be constructed in the world. It is characterized by deep burial, super length and group construction of TBM. Based on the geological features and conditions of the research areas as well as large quantity of geological surveys and test data, the main engineering geological problems in deep-buried and super-long tunnels are investigated, and the combined construction scheme of TBM and drilling-blasting method is proposed. The highlights, difficulties and key techniques in the construction of the project are preliminarily analyzed and discussed, including sub-tunnel construction of deep-buried tunnel and selection and layout of TBM-entering tunnel patterns, section-by-section construction of super-long tunnel and optimization of TBM tunneling schemes, group construction of TBM and high-efficient operation and management of the auxiliary system, forecast of geological disasters and prevention and control of risks, and deformation control of soft rock and safe tunneling in fault zones. It may provide technical support for the design and manufacturing of TBM and the construction of large interregional water diversion and long water transfer projects.