大跨双幅刚构-连续梁桥最大双悬臂阶段风致效应分析  

Wind-Induced Effect on Long-Span Twin-Deck Rigid Frame-Continuous Girder Bridges at Maximum Double Cantilever Stage

作　　者：王博 白杨 郑恒斌[2] 王伟 张敏[2] WANG Bo;BAI Yang;ZHENG Hengbin;WANG Wei;ZHANG Min(CCCC-SHEC Fifth Engineering Co.,Ltd.,Xi′an 710119,China;College of Water Conservancy and Civil Engineering,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]中交二公局第五工程有限公司,陕西西安710119 [2]华南农业大学水利与土木工程学院,广东广州510642

出　　处：《世界桥梁》2025年第2期81-89,共9页World Bridges

基　　金：广东省基础与应用基础研究基金项目(2021A1515012280);广州市科技局基础与应用基础研究项目(2023A04J1559)。

摘　　要：为确保大跨桥梁施工期抗风安全,以沿海地区某主跨200 m的双幅预应力混凝土刚构-连续梁桥为背景,研究其最大双悬臂阶段在双幅邻近主梁气动干扰效应下结构的风致效应。基于计算流体动力学(CFD)技术,考虑双幅主梁间的气动干扰效应计算双幅主梁典型断面处的三分力系数;基于本征正交分解(POD)的脉动风场快速模拟方法和Davenport准定常气动理论,采用抖振时域法计算分析0°风攻角下最大双悬臂阶段桥梁在脉动风作用工况、平均风与脉动风联合作用工况下的位移和应力。结果表明:迎风侧主梁气动力系数显著大于背风侧,采用迎风侧气动力系数作为抗风分析依据;风荷载作用下主梁横、竖向最大瞬态位移响应分别为71.1 mm和43.9 mm,对应挠跨比分别为1/1 392和1/2 255,均小于规范限值1/300;各位置处主梁及主墩考虑施工状态和风荷载作用的累计应力基本均为压应力,最大压应力分别为13.30 MPa和6.27 MPa,均小于规范限值,结构应力状态安全。This study investigates the wind-induced effects on the long-span,twin-deck,rigid frame-continuous girder bridge at the maximum double cantilever stage,when the stability of the structure is challenged by the aerodynamic interference between the two decks.A bridge of this type with a main span of 200 m in the coastal area is used as a case.Following the principles of the computational fluid dynamics(CFD),the three-component force coefficients at typical cross-sections of the twin-deck bridge are calculated,considering the aerodynamic interference between the two decks.Subsequently,based on the proper orthogonal decomposition(POD)rapid simulation method and Davenport quasi-steady aerodynamic theory,the buffeting time domain method is employed to calculate and analyze the displacements and stresses of the bridge at the maximum double cantilever stage under the action of fluctuating wind and the combined action of average and fluctuating winds,respectively,assuming the attack angle to be 0°.The results demonstrate that the aerodynamic coefficients of the windward deck are significantly greater than those of the leeward deck,thus being used as the data for wind resistance analysis.Under wind loads,the maximum lateral and vertical transient displacements of the decks are 71.1 mm and 43.9 mm,respectively,corresponding with the deflection-span length ratios of 1/1392 and 1/2255,less than the limit value of 1/300 prescribed by the codes.The cumulative stresses in the specific locations of the decks and piers all mark compressive stresses,considering the construction state and wind actions,with the maximum compressive stresses in the decks and main piers reaching 13.30 MPa and 6.27 MPa,respectively,all less than the code-suggested values,proving that the structural stress state is safe.

关 键 词：刚构-连续梁桥 双幅桥面 气动干扰效应 最大双悬臂阶段 风致效应 抖振时域分析 数值模拟 

分 类 号：U448.2[建筑科学—桥梁与隧道工程] U441.3[交通运输工程—道路与铁道工程]