广州明珠湾大桥主桥中跨合龙技术  

Central Span Closure Techniques for Main Bridge of Mingzhu Bay Bridge in Guangzhou

作　　者：赵健 尹光顺[3,4] 安路明 刘银涛 任延龙 ZHAO Jian;YIN Guang-shun;AN Lu-ming;LIU Yin-tao;REN Yan-long(China Railway Construction Bridge Engineering Bureau Group Co. , Ltd. , Tianjin 300300, China;Xi′an University of Architecture and Technology, Xi′an 710055, China;State Key Laboratory of Health and Safety of Bridge Structures, Wuhan 430034, China;China Railway Bridge Science Research Institute, Ltd. , Wuhan 430034, China)

机构地区：[1]中国铁建大桥工程局集团有限公司,天津300300 [2]西安建筑科技大学,陕西西安710055 [3]桥梁结构健康与安全国家重点实验室,湖北武汉430034 [4]中铁大桥科学研究院有限公司,湖北武汉430034

出　　处：《桥梁建设》2021年第4期127-133,共7页Bridge Construction

基　　金：天津市科技开发项目(19YDL ZSF00030);中国铁建股份有限公司科技开发项目(2018-C05);中国铁建大桥工程局集团有限公司科技研究开发课题(DQJ-2019-B24)。

摘　　要：广州明珠湾大桥主桥为(96+164+436+164+96+60)m中承式钢桁拱桥,采用双层桥面布置,主梁采用N形三主桁钢桁梁结构。主桥采用斜拉扣挂法、拱梁同步架设;中跨合龙时,拱肋与主梁分别采用“多点同步合龙”与“节点拼装合龙”法进行先拱后梁施工,以提高大桥的合龙效率。通过敏感性分析确定该桥采用26号、29号墩顶、落梁为主,竖向、横向、纵向顶拉为辅的合龙措施调整拱肋合龙口空间姿态。该桥中跨合龙施工中,在边跨采用抗倾覆压重设计,以控制大桥悬臂施工阶段由自重产生的倾覆力矩;在26号、29号墩顶支座处布置顶、落梁及纵移装置,以消除合龙口高差与转角位移,实现精准对位;在拱肋与主梁合龙口设置微调装置,以实现钢梁合龙口间距微调;在27号主墩设置顶推装置,使结构整体纵移0.085 m,实现上、下拱肋同步合龙;主梁合龙节点杆件拼装后,利用吊杆与顶拉装置调节高差与合龙口间距,实现大桥无应力精确合龙。The main bridge of Mingzhu Bay Bridge in Guangzhou is a half-through steel truss arch bridge with span arrangement of 96,164,436,164,96 and 60 m.The bridge accommodates two levels of decks.The main girder consists of three N-shaped trusses.The main bridge was constructed by the cable-stayed cantilever assembly method,and the erection of the arch and the installation of the main girder was carried out in parallel.To improve the closure efficiency of the bridge,the arch was closed by the multi-point closure method,while the main girder of the central span was closed by the panel point assembly method.As per the sensitivity analysis,the main girder was jacked and lowered over the top of piers 26 and 29,assisted with vertical,transverse and longitudinal jacking and pulling to adjust the spatial position of the closure gap.During the closure construction of the central span,the side spans were counterweighted to avoid collapsing and control the overturning moment induced by the self-weight of the structure during the cantilever construction process of the bridge.The devices to control the jacking,lowering and longitudinal moving of the main girder were installed at the bearings on tops of the piers 26 and 29,so as to eliminate the elevation difference of the closure gap and corner displacement,and realize accurate positioning.Fine tuning devices are installed on the arch and at the closure gap to realize the fine tuning of the space of the closure gap of steel girder.The pushing device was set at the main pier 27 to allow the structure to be integrally moved in the longitudinal direction by 0.085 m,as a result,the parallel closure of the upper and lower arch ribs was achieved.When the members at the nodes of the main girder closure gap were assembled,the hangers together with the jacking and pulling devices were relied to adjust the elevation difference and closure gap space,and finally the stress-free accurate closure of the bridge was realized.

关 键 词：中承式拱桥 三主桁钢桁拱 敏感性分析 多点同步合龙 节点拼装合龙 桥梁施工 

分 类 号：U448.224[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]