高墩大跨度空腹式刚构桥空腹区施工方法研究

为解决高墩大跨度空腹式刚构桥无法采用支架施工,且施工过程中上、下弦结构无法独立承受长悬臂的挂篮施工荷载施工难题,以主跨290 m的北盘江特大桥为例进行研究,对比分析了4种方法(双扣挂法、下弦扣挂结合上弦支架节段现浇法、下弦扣挂结合上弦支架整体现浇法和下弦扣挂结合支架支撑的上弦挂篮悬臂浇筑法)施工该桥空腹区的适用性、经济性、安全性及工期.分析结果表明,下弦扣挂结合上弦支架节段现浇法适用性较强,经济性较好,所需工期较短,对结构受力较为有利.

Study of Construction Methods for Open-Web Area of High-Rise Pier and Long Span Open-Web Rigid-Frame Bridge

To resolve the problem that the high-rise pier and long span open-web rigid-frame bridge cannot be constructed by the scaffolding method and in the construction process,the upper and lower chord structures of the open-web area of the bridge cannot independently carry the construction load of form travelers on long cantilevers,the Beipan River Bridge of the same type with a main span 290 m was cited an example and was studied.The applicability,economy,safety and construction time schedules of four kinds of the construction methods(the double stayed cantilever construction methods for both the upper and lower chords,the combined method of segmental casting,using the stayed cantilever construction for the lower chord and the scaffolding for the upper chord,the combined method of integral casting,using the stayed cantilever construction for the lower chord and the scaffolding for the upper chord and the combined method of cantilever casting,using the stayed cantilever construction for the lower chord and the scaffolding-supported form traveler for the upper chord) were compared and analyzed.The results of the analysis demonstrate that the applicability of the combined method of segmental casting,using the stayed cantilever construction for the lower chord and the scaffolding for the upper chord is fine,the economy is notable,the construction time required by the method is relatively short and the method is advantageous to the force conditions of the structures.