陡峭山谷地形大跨连续刚构桥风致响应研究  

Research on Wind Induced Response of Long-Span Continuous Rigid Frame Bridges in Steep Valley Terrain

作　　者：黄东平 HUANG Dongping(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3期87-90,140,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计划项目(2021-57)。

摘　　要：为解决陡峭山谷地形连续刚构桥施工时结构的抖动问题,以贵州省剑河至黎平高速公路PPP项目小瑶光特大桥为研究对象,运用现场实测的方法研究了山谷地形的风速场,最大双悬臂施工阶段风致结构加速度和振型响应特征。结果表明:不同监测点位置的风速存在差异,山谷遮挡和河道宽度突变会影响风速风向,乌下江陡峭山谷地形湍流现象明显;在最大双悬臂施工阶段,桥梁结构的振动以低阶振动为主,结构横弯和纵弯刚度低、抗风能力弱,风荷载对结构的整体稳定性影响较大;大跨连续刚构桥的阻尼比组成复杂,实测阻尼比在0.2~0.8之间,阻尼比在各自振频率中的分布不均,低自振频率低阶振型的阻尼比较大,高自振频率高阶振型的阻尼比较大。In order to solve the problem of structural vibration during the construction of continuous rigid frame bridges in steep valley terrain,the Xiaoyaoguang Extra Large Bridge of the PPP project on the Jianhe to Liping Expressway in Guizhou Province was taken as the research object.The wind speed field in the valley terrain,maximum wind induced structural acceleration and vibration mode response characteristics during the double cantilever construction stage were studied using on-site measurement methods.The results show that there are differences in wind speed at different monitoring points,and valley occlusion and sudden changes in river channel width can affect wind speed and direction.The steep valley terrain of Wuxia River exhibits obvious turbulence phenomena;in the maximum double cantilever construction stage,the vibration of the bridge structure is mainly low order vibration,with low transverse and longitudinal bending stiffness and weak wind resistance.Wind load has a significant impact on the overall stability of the structure;the damping ratio composition of large-span continuous rigid frame bridges is complex,with measured damping ratios ranging from 0.2 to 0.8.The distribution of damping ratios in their respective frequencies is uneven.The damping ratio of low natural frequencies and low order modes is relatively large,while that of high natural frequencies and high order modes is relatively large.

关 键 词：山谷地形 挂篮施工 悬臂法 大跨度桥梁 风荷载 动力响应 

分 类 号：U448.23[建筑科学—桥梁与隧道工程] U442.59[交通运输工程—道路与铁道工程]