大跨度钢桁梁斜拉桥快速强制合龙技术研究

Study on Rapid Forced Closure Technology of Long-span Steel Truss Girder Cable-stayed Bridge

徐州-盐城高速铁路盐城特大桥为主跨312m的双线钢桁梁斜拉桥,主梁采用悬臂架设跨中合龙的施工方法。提出了一种大跨度斜拉桥结构跨中快速强制合龙方法。首先,借助仿真技术对合龙口竖向、纵向、横向位移偏差进行分析,为其纠偏措施的选择提供依据。其次,研发了一种钢梁纵移装置,并结合温差法解决合龙杆件喂梁和合龙施工问题;提出塔梁约束释放控制法;推导出临界合龙的温度公式,确定合理的施工温度范围。最后,通过实测数据验证合龙后成型状态的可靠性。实践表明,该强制合龙技术实现了安全快速施工。

Yancheng Bridge on Xuzhou-Yancheng High-speed Railway is a double track steel truss cablestayed bridge with a main span of 312 m,and the main girder construction adopts cantilever erection midspan closure construction method. A forced closure technique for long-span cable-stayed bridge is developed. Firstly,the sensitive factors of vertical,longitudinal and transverse deformation are analyzed,which provides a reference for the selection of deviation measures with the help of simulation technology.Then,a longitudinal moving device of steel girder is developed,and the construction problem of girder feeding and closing is solved by temperature difference method. A control method of tower-girder constraint release is proposed. The formula of critical closing temperature is deduced and the reasonable construction temperature is determined. Finally,the reliability of the forming state is verified by the measured data. Practice proves that the forced closure technology realizes safe and rapid construction.