武汉鹦鹉洲长江大桥北锚碇新型沉井基础设计  

Design of New Type Caisson Foundation for North Anchorage of Yingwuzhou Changjiang River Bridge in Wuhan

作　　者：李明华[1] 杨灿文[1] 

机构地区：[1]中铁大桥勘测设计院有限公司,湖北武汉430056

出　　处：《桥梁建设》2011年第4期1-4,24,共5页Bridge Construction

摘　　要：武汉鹦鹉洲长江大桥主桥为三塔四跨悬索桥。该桥北锚碇基础经多方案比选采用多圆孔环形截面新型沉井结构。沉井中间大圆孔内设置十字形隔墙，圆环内沿圆周均布有小直径井孔。沉井总高43m，共分8节，第1节为钢壳混凝土沉井，第2～8节均为钢筋混凝土沉井。北锚碇施工中采用不排水下沉、井壁增加空气幕等措施减小施工难度及风险。采用软件FLAC3D对沉井施工过程进行数值模拟分析，评估施工安全性能、施工引起的环境效应及运营加载后锚碇基础的变形等。计算结果表明，沉井分节下沉施工过程中其结构、地面变形均满足规范要求，施工可有效避免对周围建筑物和长江大堤的不利影响。The main bridge of Yingwuzhou Changjiang River Bridge in Wuhan is a three-tower and four-span suspension bridge. After comparison of different design proposals, it was determined that a new type caisson structure of circular cross section and with multiple round wells would be used for the north anchorage foundation of the bridge. In the big size well in the center of the caisson, the crisscross diaphragm was set and along the periphery within the caisson, a number of small size wells were uniformly set. The caisson is 43 m high and has totally 8 lifts, of which the first lift is a steel shell concrete caisson and the rest parts of the caisson from the second to the eighth lifts are all of reinforced concrete caissons. In the construction of the caisson, the caisson was sunk down by no dewatering and the air curtain was provided in the caisson wall to reduce sinking difficulty and construction risk. The software FLAC3D was used to conduct numerical simulation and analysis of the construction process of the sinking and to evaluate the construction safety, the environmental effect caused by the construction and the deformation of the foundation to be applied with load after the bridge was put into operation. The results of the analysis show that in the process of sinking the caisson in lifts, the caisson structure and ground deformation can meet the relevant requirements in the codes and the adverse influence of the construction on the ambient buildings and the river dyke can be effectively avoided.

关 键 词：悬索桥 锚碇 沉井基础 设计 施工 有限元法 

分 类 号：U443.24[建筑科学—桥梁与隧道工程]