摘要
常泰长江大桥天星洲和录安洲两座专用航道桥为刚性梁钢桁拱桥,跨度布置均为(168+388+168)m,主梁采用2片主桁双层板桁组合结构,N形桁式,焊接整体节点构造,主拱采用与主梁反向的N形桁。针对该桥施工难点,进行钢梁安装方案设计。主桁杆件采用整体节点散拼,联结系采用单根杆件拼装,每节间的桥面板分为3块安装;边跨钢梁在临时支架上采用单悬臂拼装,中跨钢梁采用扣索塔架悬臂架设、跨中分步合龙钢桁拱和系梁的总体方案施工。中跨钢梁悬臂拼装时,对拱梁同步和先拱后梁2种施工方案进行综合比选可知:2种方案均满足受力要求;先拱后梁方案压重量比拱梁同步方案少60%,但工期长3个月,并增加2台吊机,拱梁同步方案的经济性更优。因此,选择拱梁同步方案。
The Tianxing Islet and Lu′an Islet special ship channel bridges of Changtai Changjiang River Bridge are rigid-girder steel truss arch bridges.The two ship channel bridges are of identical structures of three spans of 168,388 and 168 m,where each deck system consists of two lateral N-shaped trusses and orthotropic steel deck panels that accommodate two-levels of roadway.The truss members were welded together,forming integral panel points.The N-shaped trusses of the arch and the deck system are visually in reverse.Based on the construction complexities,the erection scheme selection was carried out.The main trusses were built up from integral panels,the lateral bracings were assembled from individual members,and the deck covering each truss panel consisted of three pieces in the transverse direction.The steel trusses in the side spans were assembled in a single cantilever manner on the temporary scaffolds,while the steel trusses in the central span were installed by using a cable-stayed cantilever assembly system,and the steel truss arch and the deck were all closed at midspan.To facilitate construction,the two options,either to erect the arch and the deck in parallel or erect the arch ahead of the deck,were compared.According to the comparison,both of the two options could meet the load bearing requirements.Erecting the arch first can save 60%of counterweights,but the construction schedule would be three-month longer,and two extra cranes are needed.The parallel erection of the arch and the deck is economically superior,hence recommended.
作者
李少骏
徐伟
李镇
王恒
LI Shao-jun;XU Wei;LI Zhen;WANG Heng(China Railway Major Bridge Reconnaissance & Design Institute Co. ,Ltd. ,Wuhan 430056,China;Jiangsu Provincial Transportation Engineering Construction Bureau, Nanjing 210004, China)
出处
《桥梁建设》
EI
CSCD
北大核心
2022年第1期139-144,共6页
Bridge Construction
基金
中国中铁股份有限公司科技研究开发计划项目(2020-重点-10)。
关键词
公路铁路两用桥
钢桁拱桥
悬臂拼装
扣索塔架
先拱后梁
拱梁同步
安装方案设计
rail-cum-road bridge
steel truss arch bridge
cantilever assembly
cable-stayed cantilever assembly system
arch erection ahead of deck erection
arch and deck parallel erection
installation scheme design
