摘要
宁波舟山港主通道舟岱大桥北通航孔桥为(125+250+125)m钢-混混合梁连续刚构桥,除主跨跨中85m范围主梁采用钢箱梁外,其余均采用变截面混凝土箱梁。该桥主墩墩顶混凝土主梁采用分块现浇,其余混凝土主梁采用节段预制、悬臂拼装法施工;主跨跨中钢箱梁采用2台桥面吊机整体起吊合龙。采用MIDAS Civil软件建立有限元模型,模拟桥梁施工过程,结合有限元计算进行该桥施工控制。施工中,考虑施工阶段、活载和运营阶段位移进行主梁制造预拱度控制;通过负误差动态控制主梁预制长度和角度误差;通过精确定位基准梁和调整环氧树脂胶厚度控制主梁拼装误差;通过对环境温度、合龙段吊装时钢-混结合段变形和钢箱梁变形修正进行钢箱梁制造长度控制。通过以上施工控制关键技术,混凝土主梁拼装完成时主梁轴线和高程最大悬臂拼装误差分别为15.1mm和1.4mm,钢箱梁合龙后精度在10mm以内,满足设计要求。
The north navigational channel bridge of Zhoudai Bridge,which carries part of the Ningbo-Zhoushan Port Main Link,is a continuous rigid-frame bridge with a main span of 250m and two side spans of 125m.The superstructure consists of steel-concrete hybrid girders,besides the 85m-long midspan steel box girders in the main span,the remaining parts are all composed of concrete box girders with variable cross-section.The concrete box segments on the tops of main piers were cast in situ,while the remainder were prefabricated in segments and assembled in cantilevers in the field.The steel box girders in the main span were hoisted and closed by two deck cranes.The finite element model was established by MIDAS Civil to simulate the construction process of the bridge,based on which the construction control was conducted.In the construction process,the precamber of the main girder was controlled,taking into account the construction stages,live loads and displacements in the service stage.The prefabrication length and angle errors of the main girder were dynamically controlled via negative errors.The reference girder segment was accurately positioned and the thickness of the epoxy glue was adjusted to control the main girder assembly error.The ambient temperature,deformation of steel-concrete joint section and deformation of steel box girder during installation of closure segment were modified to control the manufacturing length of the steel box girder.By implementing the techniques,the maximum main girder geometry and elevation errors were limited to 15.1mm and 1.4mm,respectively,when the cantilever assembly of the concrete box girders was finished.After closure,the accuracy of the steel box girder was less than 10mm,meeting the design requirements.
作者
刘德清
王文洋
LIU De-qing;WANG Wen-yang(State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;Wuhan Bridge and Building Works Supervision Co.,Ltd.,Wuhan 430034,China;China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2021年第1期121-129,共9页
Bridge Construction
基金
中国中铁股份有限公司科技研究开发计划课题(2017-重点-37-01)。
关键词
连续刚构桥
混合梁
悬臂拼装
预拱度
误差调整
制造长度
施工控制
有限元法
continuous rigid-frame bridge
hybrid girder
cantilever assembly
precamber
error adjustment
manufacturing length
construction control
finite element method
