大跨度公铁PC连续刚构桥下挠对比分析.doc

文档介绍：
大跨度公铁 PC 连续刚构桥下挠对比分析
吴迅,岳建军,黄仙正*
(同济大学桥梁工程系,上海 200092)
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摘要:大跨度 PC 连续刚构桥在运营过程中出现了下挠病害,尤其是公路桥,其病害程度较
铁路桥大得多,大大影响其使用功能。分析对比公铁桥梁下挠情况,能为控制公路桥的下挠
提供参考。本文首先分析了公铁设计规范所采用的徐变模式,然后利用 Midas Civil 模拟了
两座跨度相近的公路桥和铁路桥全桥施工过程,对比分析了二者的应力状态和长期变形,得
出铁路桥的应力状态有利于减小下挠的发生。最后,建议在公路桥梁预应力的配置中,应使
墩顶位置处上缘压应力略大于下缘压应力,以减小下挠病害。
关键词:PC 刚构桥;下挠;徐变模式;应力状态;长期变形
中图分类号:
Comparative Analysis of the Deflection Between Highway
and Railway Long-Span PC Continuous Rigid Frame
Bridges
Wu Xun, Yue Jianjun, Huang Xianzheng
(Department of Bridge Engineering,Tongji University,Shanghai 200092)
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Abstract:
The long-span PC continuous rigid frame bridge deflection disease occurred in service
period, especially the disease in highway bridge, is much greater than that in railway bridge and
greatly influences its using function. Analysis of highway and railway bridge deflection contrast
can provide the reference for the deflection control of highway bridge. In this paper, the difference
of creep modes used in the highway and railway design specifications was firstly analyzed. Then,
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the full bridge construction processes of one highway bridge and one similar span railway bridge
were respectively simulated by Midas/Civil. parative analysis of both the stress state and
long-term deformation, we find the railway bridge stress state will help reduce the incidence of
defl