摘要
重庆白居寺长江大桥主桥为主跨660 m的公轨两用双塔双索面钢桁梁斜拉桥。桥塔为空间曲线水滴形混凝土结构,采用爬模施工;钢桁梁为带边纵梁的倒梯形截面,利用桥面吊机进行对称悬臂施工。为确保成桥后的各项力学和线形指标满足设计要求,采用MIDAS Civil软件建立主桥施工阶段有限元模型,对塔顶偏位和应力、钢桁梁线形及斜拉索张拉进行施工监控。通过控制塔顶偏位以及关键断面应力,确保了钢桁梁施工中桥塔的安全;通过控制主桁和边纵梁的制造和安装线形,保证了钢桁梁成桥线形的控制精度;通过边、中跨1~5号索同步对称初张、6~20号索分级不对称初张及局部二次调索,提高了斜拉索的施工效率以及索力控制精度。施工监控结果表明:塔顶偏位最大偏差27 mm,钢桁梁线形最大偏差52 mm,斜拉索索力偏差在±5.6%内,均满足设计要求。
The main bridge of Baijusi Changjiang River Bridge in Chongqing is a cable-stayed bridge with a main span of 660 m.Accommodating vehicle and light rail traffic,the superstructure consists of steel trusses of inverted trapezoidal cross-section,featuring the edge stringers,which were asymmetrically assembled by launching cranes.The two pylons are spatial waterdrop-shaped concrete structures that were constructed using climbing formwork.To ensure that the mechanical properties and geometry indexes of the completed bridge would meet the design requirements,the construction process of the main bridge was numerically simulated in MIDAS Civil,to monitor and control the pylon-top displacement and stresses,alignment of steel trusses and tensioning of stay cables.The control of the pylon-top displacement and stresses in key cross-sections was critical to the safety of the pylons during the construction of steel trusses.The manufacturing and installation alignments of the main truss and edge stringers were monitored to guarantee the control accuracy of the alignment of the steel trusses after completion of the bridge.The stay cables are arranged in double cable planes.To improve the construction efficiency and tension control accuracy,the stay cables in the side spans and the stay cables No.1-No.5 in the central span were synchronously and symmetrically tensioned,the stay cables No.6-No.20 in the central span were tensioned in stages and in an asymmetrical manner,locally adjusted when necessary.The maximum pylon-top displacement was 27 mm,the maximum alignment bias of the steel trusses was 52 mm,and the tension differences among stay cables were within the range of±5.6%,all met the design requirements.
作者
周浩
郑建新
朱浩
ZHOU Hao;ZHENG Jianxin;ZHU Hao(CCCC Second Harbor Engineering Co.,Ltd.,Wuhan 430040,China;CCCC Second Harbor Engineering Construction Technology Co.,Ltd.,Wuhan 430040,China;CCCC Highway Bridge National Engineering Research Centre Co.,Ltd.,Beijing 100120,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2024年第4期141-148,共8页
Bridge Construction
基金
中国交通建设股份有限公司科技研发项目(2020-ZJKJ-PTJS13)
中交第二航务工程局有限公司科技研发项目(20190730-013)。
关键词
公轨两用桥
斜拉桥
钢桁梁
桥塔
斜拉索
悬臂施工
局部调索
施工控制
vehicle-light rail bridge
cable-stayed bridge
steel truss girder
pylon
stay cable
cantilever construction
local tension adjustment
construction control
