新型浮式坞门的挡水扶壁结构设计要点简析

Analysis of Design Essentials of Water-Retaining Wall Applied to New-type Floating Dock Gate

港珠澳大桥桂山沉管预制厂项目中,受场地预制条件的限制,深坞浮坞门选用钢筋混凝土箱型结构,但因浮坞门体型庞大,若全部采用钢筋混凝土结构,自重和浮运吃水过大,难以满足浮运的安全要求。为解决这一技术难题,经过一系列的分析研究,创新性地提出一种钢筋混凝土与钢结构组合的箱型浮坞门结构,即在传统的钢筋混凝土沉箱结构中增设一种挡水钢扶壁结构,用于替代部分混凝土壁板,从而减小浮坞门自重并降低重心高度,有效保障浮运安全。现场使用效果表明,这种新型钢-混凝土组合浮式坞门受力合理、安全可靠,可在其他类似工程中推广应用。

In Guishan project of immersed tunnel precast factory of Hongkong-Zhuhai-Macao Bridge,reinforced concrete box structure is adopted as deep-water floating dock gate subject to field condition.Large-size RC floating dock gate will lead to excessive dead-weight and floating draft,which cannot meet the safety requirements for floating transport.In order to solve this technical problem,a series of analysis and research are carried out,such innovative propose as RC-steel combination is put forward,namely,part of concrete wall is replaced with one kind of steel water-retaining wall in traditional RC caisson.The above measure reduces dead weight of floating dock gate,lowers the center of gravity,ensures safe floating transport.Field application results show that reasonable weight is put on the combined structure,which is safe,reliable,worthy of promotion and application in similar projects.