5×16m 下穿铁路框架桥顶进施工分析

摘要

天堂河（北京段）新机场改线下穿京九铁路框架桥，孔跨布置为5×16 m，全长85．6 m，是目前国内单体顶进跨度最大的框架桥。本框架桥采用5孔整体预制，整体顶进，施工中设计最大顶力为26783 t，施工难度大，安全风险高。通过 Midas Civil 有限元软件对整个施工工况进行模拟分析，为施工过程提供有效数据，进而保证施工安全稳定。最后从施工工艺、施工监测等方面的优化以保证框架桥在顶进过程中受力安全。%Tiantanghe Airport Frame Bridge (Beijing section),which under-passing the Beijing-Kowloon Railway with a total length of 85.6 m (span arrangement is 5 ×16 m),is currently the largest span with single jacking method in China. The framework is prefabricated and jacked (the largest jacking force of 26 783 t)by 5-span.Considering the great difficul-ty and high risk in construction,Midas Civil is used for simulation analysis of the entire working conditions to provide valid data for construction process and ensure the security and stability of the construction.The force security of the frame bridge in jacking is optimally guaranteed by construction technology,construction monitoring and so on.