越江盾构隧道建设面临的挑战、对策及思考

Challenges, Countermeasures and Reflections on the Construction of Cross River Shield Tunnels

随着我国经济的发展,越江盾构隧道建设量的增加,越江隧道的盾构直径、掘进距离、隧道埋深不断增大,建设难度也逐渐上升。文章针对超大直径越江盾构隧道的设计和施工中的关键技术问题进行了深入研究。结合越江隧道“长、大、高、深”的主要特点制定相应的对策。针对超长隧道的防火疏散问题,提出了新型疏散模式与通风排烟策略;在超大直径盾构的纵向变形控制方面,采用双液同步注浆技术控制隧道上浮;面对高水压环境下的防水难题,优化了双道密封垫的布局;面对覆土冲刷或淤积引起隧道结构变形的问题,创新提出DDCI新型连接构造,提升大直径盾构隧道结构承载能力;同时对装配式内部结构和绿色环保型隧道路面铺装等附属工程的新技术与新材料进行了研讨,并对未来大直径越江盾构的发展进行深入思考。

With the development of China's economy,the construction volume of cross river shield tunnels has increased.At the same time,the shield diameter,excavation distance,and tunnel burial depth of cross river tunnels are constantly increasing,and the construction difficulty is also increasing.This paper conducts an in-depth research on the key technical issues in the design and construction of ultra large diameter underwater shield tunnels.Develop corresponding countermeasures based on the main characteristics of the"long,large,high,and deep"cross river tunnel.A new evacuation mode and ventilation and smoke exhaust strategy have been proposed for the fire evacuation problem of ultra long tunnels.In terms of longitudinal deformation control of ultra large diameter shield tunneling,dual liquid synchronous grouting technology is used to control the floating of the tunnel.In the face of waterproofing difficulties in high water pressure environments,the layout of dual sealing gaskets has been optimized.Faced with the problem of deformation of tunnel structures caused by soil erosion or sedimentation,a new type of DDCI connection structure is proposed to improve the bearing capacity of large-diameter shield tunnel structures.At the same time,discussions were conducted on new technologies and materials for auxiliary projects such as prefabricated internal structures and green environmental protection tunnel pavement,and in-depth consideration was given to the development of large-diameter cross river shield tunneling in the future.