扣索风致振动引发大跨悬浇施工拱桥内力变形变化研究  

Research on the Internal Force and Deformation Changes of Large⁃Span Cantilever Casting Construction Arch Bridge Caused by Wind⁃Induced Vibrations from Fastening Stays

作　　者：申晓平 SHEN Xiaoping(China Railway 17th Bureau Group City Construction Co.Ltd.,Gui′an Guizhou 550025,China)

机构地区：[1]中铁十七局集团城市建设有限公司,贵州贵安550025

出　　处：《铁道建筑技术》2024年第7期103-107,共5页Railway Construction Technology

基　　金：中铁十七局集团有限公司科技研究开发项目(2022-A06)。

摘　　要：以金仁桐高速公路娅石庆特大桥为研究对象,为评估施工期受风荷载影响的施工安全,运用数值模拟的方法建立三维模型,分析扣索风致振动引发大跨悬臂浇筑施工拱桥的内力和变形变化规律。结果表明:风荷载引起1/4跨节点位置处拱桥竖向振动位移远小于最大悬臂段的竖向振动位移,最大悬臂端的风荷载竖向振动响应最大可达到13.38 cm,为前者最大竖向位移的3.7倍;振动频率小于基阶频率时,拱桥最大悬臂端的竖向位移功率谱大于1/4跨节点位置处的竖向功率谱,而振动频率大于基阶频率时,两位置处的竖向位移功率谱接近;扣索风致振动时,最大悬臂阶段拱桥拱脚位置的轴力最不利,1/8跨节点位置处弯矩最大,拱圈顶板最大拉应力位于1/2跨节点位置处;拱圈底板最大拉应力位于1/8跨节点位置处。This article takes the Yashiqing Extra Large Bridge,located on the expressway from Jinsha to Tongzi via Renhuai,as the research object to evaluate the construction safety impacted by wind during the construction period.The numerical simulation method is used to establish a three⁃dimensional model and analyze the internal force and deformation changes of large⁃span cantilever casting construction arch bridges caused by wind⁃induced vibration from fastening stays.The results indicate that the vertical vibration displacement caused by wind load at the 1/4 span of the arch bridge,is significantly smaller than that of the maximum cantilever section.The maximum vertical vibration response of the wind load at the end of the maximum cantilever section can reach 13.38 cm,which is 3.7 times the maximum vertical displacement of the former position.When the vibration frequency is lower than the fundamental frequency,the vertical displacement power spectrum at the maximum cantilever of the arch bridge is greater than that at the 1/4 span.Conversely,when the vibration frequency exceeds the fundamental frequency,the vertical displacement power spectrum at the two positions is close.When the wind⁃induced vibration comes from fastening stays,the axial force at the arch foot position of the arch bridge during the maximum cantilever stage is the most unfavorable.The maximum bending moment occurs at the 1/8 span,while the maximum tensile stress of the arch ring′s top plate is located at the 1/2 span.Additionally,the maximum tensile stress of the arch ring′s bottom plate is situated at the 1/8 span.

关 键 词：大跨度拱桥 悬臂浇筑施工 扣索 风致振动 内力 变形 

分 类 号：U441[建筑科学—桥梁与隧道工程] U445.466[交通运输工程—道路与铁道工程]