复杂海域环境下公铁两用斜拉桥主塔基础施工技术研究

Research on the Construction Technology for Main Tower Foundation of Highway and Railway Cable⁃Stayed Bridge in Complicated Sea Area Environment

桃夭门公铁两用大桥墩基础面临紧邻既有大型桥梁、深水急流、海蚀陡崖、倾斜裸岩、窄水域、重航运等复杂恶劣环境,给下部结构施工带来极大的挑战。为解决复杂海域环境下主塔群桩、承台的施工问题,针对大桥5#主墩基础,提出“先桩后堰+钓鱼法形成平台+回转钻机和冲击钻成孔”的施工工艺;针对大桥6#主墩基础,提出“回填筑岛+冲击钻孔”的施工工艺;研究成果有效解决了裸岩平台生根、急流钢管和钢围堰精准沉放、大直径桩基成孔等控制技术难题,可为类似工程提供经验参考。

The pier foundation of the Taoyaomen highway and railway bridge is facing complex and harsh environments,including neighboring major bridge,deep water rapids,sea eroded cliffs,inclined bare rock,narrow waterway,and heavy shipping,all of which present significant challenges to the substructure construction.In order to solve the construction problems of the main tower group piles and bearing platforms in complex marine environments,a construction process for 5#main pier foundation is proposed,comprising“pile installation followed by weir formation using a fishing method,platform creation,and the utilization of rotary and impact drilling rigs”.For the 6#main pier foundation,a construction process of“backfill island creation coupled with impact drilling”is proposed.The research results have effectively tackled technical challenges related to the stabilization of bedrock platforms,precise sinking of rapid flow steel pipes and steel cofferdams,and drilling of large⁃diameter pile foundations.These findings provide valuable insights and practical experience for similar engineering projects.