怒江特大桥基于拱上顶推钢梁仿真分析研究

Study on Simulation Analysis of Nujiang Special-large Bridge Based on Arch Top Pushing Steel Beam

目前,国内外已有超过1 000座桥梁都是利用顶推施工方法建成,研究成果也相对成熟,但对于大跨度上承式钢桁架拱桥而言,研究成果较少,特别是对于利用拱上平台作为拼装场地进行顶推施工的例子更是为数不多.本文根据基于拱上平台的顶推施工法进行钢梁支反力变化趋势研究,发现由于顶推过程的重复性,顶推钢梁的支反力变化趋势呈现周期性的特点.对于墩顶支座反力来说,当导梁距离该主墩较近时,该主墩顶支座反力随施工过程变化较大;当导梁距离某一主墩较远时,该主墩的支座反力随施工过程变化较小,这对同类型桥梁顶推施工具有一定指导作用,并为日后相关研究提供参考依据.

At present,more than 1000 bridges at home and abroad have been built by jacking construction method,and the research results are relatively mature,but for long span deck steel truss arch bridges,the research results are less,especially,there are few examples of pushing construction by using the platform on the arch as the assembling site.In this paper,according to the method of pushing construction on the platform on the arch,the changing trend of the reaction force of steel beam is studied,it is found that the reaction force of the steel beam is periodie because of the repeatability of the pushing process.For the counter-force of the pier top support,when the guide beam is close to the main pier,the reaction of the support on the top of the main pier changes greatly with the construction process;when the guide beam is far from a main pier,the reaction force of the support of the main pier changes lttle with the construction process.It has a certain guiding effct on the jacking construction of similar bridges and provides reference for future related studies.