宽幅组合梁斜拉桥合龙控制关键技术研究

Study on Key Technology of Closure Control for Wide Composite Beam Cable-stayed Bridge

泰东河大桥为主跨270 m的双塔双索面叠合梁斜拉桥,中跨合龙时采用单侧桥面吊进行吊装。中跨合龙段钢梁需提前进行配切,为实现桥梁无应力合龙,对影响合龙的关键因素进行系统分析,包括桥面吊机重量误差、体系温差等环境参数以及悬臂端施工临时荷载等因素。根据各参数影响程度,提出无应力合龙控制对策以及合龙段合理配切量的确定方法。此外,考虑到实际施工时合龙口两端存在一定误差,研究提出汽车吊移动载和拉索索力调整等快速化调控合龙口姿态的方法。研究成果可较好指导现场施工,并为同类工程提供借鉴。

Taidong River Bridge is a double-pylon double-plane superposed beam cable-stayed bridge with the main span of 270 m.The unilateral deck hoist is used in the closure of middle span.Owing to that the steel beam of middle span closure section is required to cut in advance,and in order to realize the unstressed closure of bridge,the key factors influencing the closure are systematically analyzed including the environmental parameters of weight error and system temperature difference of deck hoist,and the factors of temporary loads of cantilever end construction.Based on the influences of various parameters,the control countermeasures for the unstressed closure and the determination method of reasonable cutting amount for closure section are put forward.In addition,by considering a certain error also existing at two ends of final closure during the practical construction,the methods of adjusting the truck crane mobile load and stayed cable force to rapidly adjust and control the posture of final closure are studied and put forward.The study result can better guide the field construction and provide the reference for the similar projects.