广大铁路80 m跨度系杆拱桥线形控制技术

Alignment Control Technology of 80 m Span Tied Arch Bridge on Guangtong-Dali Railway

针对支架现浇大跨度钢筋混凝土系杆拱桥施工周期长、不可控因素多、成桥线形控制难度大等问题,以广大(广通—大理)铁路支架现浇80 m跨度系杆拱桥线形控制为例,采用有限元软件MIDAS/Civil建立模型,对该桥进行了全施工节段仿真分析,得到各施工阶段理论变形值。通过控制现场立模标高,对各受力工况下挠度进行监测和调整,有效保证了系梁、拱肋最大挠度满足设计要求,确保了成桥线形符合设计要求,可为同类型桥梁工程线形控制提供参考。

The construction period of cast-in-place long span reinforced concrete tied arch bridge with support is long,and there are many uncontrollable factors,so it is difficult to control the finished bridge alignment.Taking the alignment control of 80 m span tied arch bridge on Guangtong-Dali railway with cast-in-place support as an example,the finite element software MIDAS/Civil was used to establish the model,the whole construction segment simulation analysis of the bridge was carried out to obtain the theoretical deformation values of each construction stage.By controlling the elevation of formwork erection on site,monitoring and adjusting the deflection under various stress conditions,the maximum deflection of tie beam and arch rib is effectively ensured to meet the design requirement,and the finished bridge alignment is guaranteed to accord with the design requirement.It can provide reference for alignment control of the same type of bridge engineering.