超特长隧洞集群TBM试掘进阶段存在的问题与施工技术发展方向

Some Issues during TBM Trial Advance of Super-long Tunnel Group and Development Direction of Construction Technology

北疆供水二期工程总长540 km,其中隧洞段长度516 km。隧洞采用以TBM为主并结合钻爆法进行施工,其中支洞施工采用2台TBM,正洞施工采用18台TBM和3台盾构。单台掘进长度均超过15 km,最长掘进26km。TBM施工面临着集群掘进、不良地质及极硬岩穿越、超长距离施工等风险和难题,对隧洞的设计与施工技术提出了新的挑战。通过试掘进阶段的工作总结与分析,为进一步提高TBM的安全高效掘进技术水平,文章提出了超特长隧洞TBM施工今后发展的几个研究方向:1)适应TBM快速掘进的实时超前地质预报技术;2)地质适应性更强的TBM装备;3)智能化掘进技术;4)设备状态实时监测技术;5)围岩分级方法及相应的支护体系;6)辅助破岩技术;7)超长距离隧洞独头高压通风技术;8)超长距离皮带运输技术。通过改进TBM设备性能、优化隧洞设计和施工技术,从而提高设备对各种地质的适应能力,实现超长隧洞TBM的安全高效掘进。

The total length of the water transfer project phase Ⅱ is 540 km in the northern area of Xinjiang Uygur Autonomous Region of China, of which the total length of tunnels is about 516 km. The tunnel boring machine (TBM) and drilling & blasting method were adopted for the tunnel construction, the main tunnels include 18 TBM tunnelling sections and 3 shield tunnelling sections, and the branch tunnels include 2 TBM tunnelling sections. The tunnelling length of single TBM is more than 15 km, and the maximum tunnelling distance is up to 26 km. It poses unprecedented challenges on the tunnel design and construction technique due to the group driving, adverse geology and extreme hard rock, long tunnelling distance by TBM and other construction risks and difficulties. Based on the summary and analysis of the TBM performance in the trial tunnelling, several aspects on the development directions of TBM construction of super-long tunnels were put forward to improve the technical level of safe and efficient TBM tunnelling. Namely, real-time advance geological prediction technique for rapid TBM excavation should be studied;developing of the TBM equipment with better geologic adaptability should be conducted;the intelligent TBM tunnelling technique should be studied;the real-time monitoring technique for TBM equipment state should be studied;the surrounding rock classification and corresponding supporting system should be studied;the auxiliary rock breaking technique should be developed;the one-end high-pressure ventilation technique for the super-long tunnel should be studied;the belt conveyor transportation technique should be developed for the super-long tunnel. By improving performance of TBM equipment and optimizing tunnel design and construction method, the adaptability of TBM equipment to various geological conditions is increased and safe and efficient TBM tunnelling for super-long tunnels is realized.