沪通长江大桥主航道桥施工关键技术  

Key Construction Techniques for Main Ship Channel Bridge of Hutong Changjiang River Bridge

作　　者：李军堂[1] 潘东发[1] LI Jun-tang;PAN Dong-fa(China Railway Major Bridge Engineering Group Co., Ltd., Wuhan 430050, China)

机构地区：[1]中国中铁大桥局集团有限公司

出　　处：《桥梁建设》2019年第5期9-14,共6页Bridge Construction

基　　金：中国铁路总公司科技研究开发计划项目（2014G004-B）~~

摘　　要：沪通长江大桥主航道桥为主跨1 092 m的双塔钢桁梁斜拉桥。主航道桥6个桥墩均采用沉井基础,沉井上部为钢筋混凝土结构,下部为钢结构;桥塔采用钻石形混凝土结构,高330 m;主梁采用三主桁N形桁架结构。该桥施工时采取了多项关键技术:主墩钢沉井采用整体制造、充气助浮出坞浮运,定位时采用“大直径钢管桩+混凝土重力锚”锚碇系统及液压连续千斤顶多向快速定位技术施工;边墩、辅助墩钢沉井采用内部大直径钢管桩定位技术施工;沉井百米水深下的基底地形、刃脚埋深及浮土厚度采用声呐、超声波、水下机器人以及海床式静力触探系统等多种方法进行探测;在主墩基底与封底混凝土间埋置深水自平衡荷载箱,以测试主墩沉井的基底承载力;超高桥塔混凝土采用了降粘、抗裂技术施工;桥塔锚固区重型钢锚梁采用立式预制拼装、现场整体安装方案施工;钢桁梁采用大节段整体制造、架设技术施工。The main ship channel bridge of the Hutong Changjiang River Bridge is a two-pylon steel truss girder cable-stayed bridge with a main span of 1 092 m. All the six piers of the bridge stand on caisson foundations. Each caisson consists of the upper reinforced concrete structure and the lower steel structure. The pylon is a diamond-shaped concrete structure rising 330 m. The main girder consists of three N-shaped trusses. A number of key techniques have been employed in the construction of the bridge. The steel caisson is monolithically fabricated, floated out of the dock with the assistance of air bags, and positioned by a multi-directional fast positioning system that contains the anchorage system of the combined use of large-diameter steel tube piles and concrete gravity anchors as well as the continuous hydraulic jacks. The steel caisson of the side and auxiliary piers are positioned by using the internal large-diameter steel tube piles. The condition of the ground where the base of the caisson will touch after sinking for more than one hundred meters, the burying depth of the cutting edges and the thickness of regolith are detected by sonar, ultrasonic waves, underwater robot and the sea-bed cone penetrometers. The deep-water self-balanced load box is embedded between the base of the main pier and the base sealing concrete to test the bearing capacity of the base of the main pier caisson. The viscosity reducing and cracking prevention techniques are employed during the concreting of the very high pylons. The heavy steel anchor beams in the anchorage area of the bridge pylon are vertically prefabricated and assembled, and then monolithically lifted and installed at the bridge site. And the steel truss girder is divided into large segments that can be monolithically fabricated and installation.

关 键 词：公路铁路两用桥 斜拉桥 钢桁梁 沉井 锚碇系统 基底检测 混凝土降粘抗裂 钢锚梁 施工技术 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]