港珠澳大桥沉管隧道最终接头合龙施工技术

Closure construction technology for final joint of immersed tunnel of Hongkong-Zhuhai-Macao Bridge

港珠澳大桥沉管隧道最终接头位于E29沉管S8节段与E30沉管S1节段之间,距离东岛岛头约580 m,管底最低标高-27.937 m,处于半径为5500 m曲线段的钢壳混凝土结构,其水下合龙焊接施工是整个工程施工中风险最大的子工程。为最大限度降低施工风险,对施工技术不断进行优化,通过施工前期模拟演练,摸索出一套成熟、可靠的水下焊接施工方案,最终在实战中水下合龙焊接一次性焊接合格率达97.8%,为港珠澳大桥顺利贯通做出了重大贡献,创造了诸多世界之最。

The final joint of the Hongkong-Zhuhai-Macao Bridge immersed tunnel is located between the S8 section of the E29 immersed tube and the S1 section of the E30 immersed tube,about 580 m from the head of the East Island,the lowest elevation of the tube bottom is-27.937 m,and the steel shell concrete structure is located in the curve section with a radius of5500 m.Its underwater closure welding construction is the most risky subproject in the entire project construction.In order to minimize construction risks and continuously optimize the construction technology,a set of mature and reliable underwater welding construction plan was found through pre-construction simulation exercises.In the end,the underwater welding task was completed with a one-time welding pass rate of 97.8%,which has made a major contribution to the smooth completion of the Hongkong-Zhuhai-Macao Bridge and created many of the best in the world.