超宽框架桥顶进施工设计

摘要

以国内最大单体顶进框架桥—天堂河（北京段）新机场改线下穿京九铁路工程为例，详细介绍下穿既有铁路的工程的设计方案，通过空间有限元模型进行超宽框架桥仿真分析指导施工图设计，同时根据以往超宽顶桥工程中常见的病害及施工风险，设计过程中采取有效措施减小了裂缝通病，解决了超宽框架桥不均匀顶力、不均匀沉降、顶力过大、接触网上桥、应力复杂的问题。考虑本项目规模大，结构为多次超静定，应力复杂，首次在顶进框架桥中采用了应力监测系统，并与计算值进行了对比，监测结果与理论计算趋势基本一致。%Taking the largest single jacking frame bridge-Paradise River New Airport Line (Beijing section)underpassing Beijing-Kowloon Railway Engineering as an example,the detailed project design scheme of underpassing existing railway is introduced in this thesis.Ultra-wide frame bridge simulation analysis is used to guide construction drawing design through the space finite element model.Meanwhile,according to the common diseases and construction risks in previous engineer-ing of ultra-wide jacking bridge,the paper takes effective measures to reduce common crack,which could solve the problem of uneven jacking force,uneven settlement,overlarge jacking force,overhead contact line on bridge and complex stress of ultra wide frame bridge.Considering the large scale of this engineering,which the structure is indeterminate and stress is complex,stress monitoring system is firstly used in the jacking frame bridge,the monitoring result are compared with calcu-lated value,which shows the value trend consistent.