千米级不对称斜拉桥主跨合龙施工关键技术  

Key Closure Techniques for Main Span over 1000 m of Asymmetrical Cable-Stayed Bridge

作　　者：王昌喜 章斌 左翼 WANG Chang-xi;ZHANG Bin;ZUO Yi(CCCC-SHEC First Highway Engineering Co.,Ltd.,Wuhan 430012,China;Hubei Jiaotou Construction Group Co.,Ltd.,Wuhan 430050,China)

机构地区：[1]中交二公局第一工程有限公司,湖北武汉430012 [2]湖北交投建设集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2021年第5期116-122,共7页Bridge Construction

基　　金：中交二公局委托项目(X0104003-JSFW-2020-0013);湖南省教育厅资助项目(18A202);湖南省科技厅资助项目(2020JJ4310)。

摘　　要：嘉鱼长江公路大桥主桥为主跨920 m的非对称高低塔单侧混合梁斜拉桥,北边跨混凝土主梁采用支架法施工,主跨及南边跨钢箱梁采用悬臂拼装法施工。该桥主跨2019年5月30日合龙,设定合龙温度(22℃)与设计基准温度(15℃)偏差较大,采用几何控制法进行合龙施工。在主跨合龙前,考虑温度影响修正合龙段制作长度,得到合龙温度条件下的梁长为4.3428 m;考虑高温的影响设计并安装4台顶推阻尼器;利用顶推阻尼器完成顶推,调整合龙姿态并合龙。合龙姿态调整时,基于激光传感控制并调整合龙口宽度;采用临时荷载为主、斜拉索索力为辅的措施调整合龙口相对高差;通过对角交叉倒链调整轴线相对偏差。主跨合龙后,合龙口宽度及标高误差均小于5 mm,且合龙焊缝宽度均匀、无明显错台,满足设计要求。The main bridge of Jiayu Changjiang River Highway Bridge is a cable-stayed bridge with a main span of 920 m,featuring its asymmetrical hybrid superstructure.The concrete box girders in the north side span was erected on scaffolds,while the steel box girders in the main span and south side span were installed by the cantilever assembly method.The main span was closured on May 30,2019.Since there was a big difference between the temperature set for the closure on site(22℃)and the design benchmark temperature(15℃),the geometry of the structure should be controlled.Before the closure of the main span,the length of the closure segment computed under the closure temperature was 4.3428 m,when the influence of temperature was counted into the modification of the manufacturing length of closure segment.To address the high temperature issue,four jacking dampers were employed to assist the push-out of the closure segment and adjust the position of the closure segment.During the position adjustment,the laser sensors based geometry control system was used and the width of the closure gap was adjusted.The elevation difference at the closure gap was tuned up mainly through the control of temporary loads,complemented by cable force adjustment.The relative deviation of the superstructure axis was adjusted via the crosswise chain blocks.After closure,the errors of closure gap width and elevation are all less than 5 mm,the widths of the closure welds are constant,no obvious staggering can be seen,proving that the closure of the main girder meet the design requirements.

关 键 词：斜拉桥 混合梁 钢箱梁 合龙 顶推阻尼器 几何控制法 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]