双层钢桁梁斜拉桥关键施工技术

Key Construction Technology of Double-deck Steel Trussed Cable-stayed Bridge

摘要:

大跨度钢桁架桥因结构轻便美观且承载能力强而被广泛应用于跨江跨河桥梁工程中。宁波市西洪大桥为独塔双层钢桁梁斜拉桥，跨径82 m+138 m+116 m，总长336 m，桥梁主桥跨余姚江。为确保下方河道通航，综合考虑施工成本、水上施工安全性等条件，通过对顶推法、支架法等常见钢桁架桥施工技术的研究分析，设计了一种适应西洪大桥的新型临时支架体系，即在钢桁梁节点下设置预留航行通道的钢管桩支撑体系，以完成双层钢桁梁的安装。对于双层钢桁梁桥钢主桥施工相关的临时支架体系设计验算和施工、钢桁架组拼与栓接施工控制、钢桁架桥线形控制等关键技术进行的分析和介绍，可为今后同类工程提供参考。

Abstract:

Long-span steel trussed bridge is widely used in the river-crossing bridge projects because of its lightweight and beautiful structure and strong load-bearing capacity. Ningbo Xihong Bridge is a one-pylon double-deck steel trussed cable-stayed bridge with a span of 82 m+138 m+116 m. Its total length is 336 m, and its main bridge spans the Yuyao River. In order to ensure the navigation of the river channel below, taking into account the construction cost, water construction safety and other conditions, through the research and analysis of the common steel trussed bridge construction techniques such as incremental launching method and bracket method, a new type of temporary bracket system suitable for Xihong Bridge is designed, which is set up the steel pipe pile bracing system under the steel trussed nodes in order to complete the installation of the double-layered steel truss girders. The key technologies of design, checking calculation and construction of temporary bracket system related to the construction of the main steel bridge, construction control of steel truss group assemble and bolting, and control of the steel trussed bridge alignment of the double-deck steel trussed bridge are analyzed and introduced, which can provide the reference for the similar projects in the future.