大跨径简支钢—混凝土组合梁桥设计分析

介绍某跨径61m简支钢-混凝土组合梁桥的设计。为保证结构设计的经济合理、施工过程的安全可靠,在设计过程中进行详细的方案比较和计算分析。由分析可知:对于大跨径组合梁,可以采取在跨中附近设置临时墩的施工方法,使设计更经济,也能保证结构在施工过程中的安全,同时还能保证地面道路的正常通行。通过与槽形截面比较,组合梁的钢梁采用方便施工的箱形截面。收缩徐变使钢-混凝土组合梁发生应力重分布现象,将引起钢梁应力增大;温差荷载在组合梁梁端至跨中的一定范围内产生水平剪力,设计抗剪连接件时不容忽视。

DESIGN AND ANALYSIS OF A LONG SPAN SIMPLY-SUPPORTED STEEL-CONCRETE COMPOSITE GIRDER BRIDGE

This article described the design of a 61 m span simply-supported steel-concrete composite girder bridge. To ensure the economical and reasonable structural design,safety and reliability in construction process, during the design process it was carried out a detailed scheme comparison and calculation.The following conclusions were got：1） For a long span composite beam, establishing temporary support in the vicinity of the midspan,could make the design more economical, also ensure the structural safety in the construction process and the normal passage of the road under the bridge;2） As compared with groove cross-secition, box secton was used for the steel girder of composite beam,which was convenient for construction;3）The shrinkage and creep made stress redistribution occur in the steel-concrete composite beam which would increase the stress of the steel girder;4） The temperature difference load produced the horizontal shearing force within a certain range from the end to midspan of the composite beam, it should not be neglected in the design of a shear connector.