临时支墩在大跨度钢桁拱桥梁架设中的应用

摘要

研究目的:大跨度钢桁拱桥架设施工过程中钢梁局部杆件应力和变形大于桥梁使用过程中的应力和变形,为此在施工此类桥梁过程中会采用临时设施辅助施工,吊索塔架是常用的结构形式,临时支墩目前国内同类桥梁尚无使用先例,根据柳州维义大桥,钢桁拱跨度大、横向稳定性弱的特点,对该桥施工关键技术进行研究,解决支墩法架设大跨度钢桁拱的关键施工技术问题.研究结论:桥梁施工中最简单、常用的临时支墩作为钢桁拱外部辅助构件适用于大跨度钢桁拱桥架设施工,能够满足对钢桁拱的线形调整,并通过纵横移及标高控制等主动控制技术实现钢桁拱的拱和系杆的合龙,避免了钢桁拱桥的整体起落操作,简化了钢桁拱桥梁的合龙调整措施.%Research purposes:The local stress and deformation of the member bar of the steel girder of the large steel truss arch bridge in the course of the erection are bigger than those in the usage course of the bridge. Therefore, the temporary facility like the suspension cable tower is often used for construction of such kind of bridge. The temporary buttress has never been used for construction of such kind of bridge in China. As the Weiyi Bridge in Liuzhou has features of the big span of the steel truss arch and the poor lateral stability, the research is done on the key construction technologies of this bridge for using the buttress to erect the large span steel truss arch bridge.Research conclusions:As the simplest and the most commonly - used means, the temporary buttress can be used as the external auxiliary member of the steel truss arch for erecting the large span steel truss arch bridge, and by using it, the requirement of the linear adjustment for the steel truss arch can be met. By using active control technologies for controls of the vertical and horizontal shifts and the elevation, the arch and tie bar of the steel truss arch can be gathered up, the up and down operation of the whole steel truss arch bridge can be avoided and the measures for the closure adjustment of the steel truss arch bridge can be simplified.