Y型沟谷桥址区风特性的数值模拟研究  

Numerical Simulation on Wind Characteristics at Y-shaped Valley Bridge Site

作　　者：朱佩章[1] 胡博 刘智[1] ZHU Pei-zhang;HU Bo;LIU Zhi(CCCC First Highway Consultants Co.,Ltd.,Xi’an,Shaanxi 710075,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西西安710075

出　　处：《公路交通科技》2024年第4期65-72,共8页Journal of Highway and Transportation Research and Development

基　　金：国家重点研发计划项目(2021YFB2600404);陕西省创新能力支撑计划项目(2022TD-16)。

摘　　要：复杂山区的风场特性不同于平原地区,风场十分复杂,没有较为统一的规律,对大跨度桥梁的结构振动影响较大。为了研究复杂山区地形对桥址区风场特性的影响规律,以某座位于多条沟谷交汇谷口的斜拉桥桥址区为工程背景,基于ALOS数字高程地形模型,通过CFD数值模拟的方法,计算了不同风向来流下桥位处的风场特性。分析了桥址区主要的几条沟谷和桥位处局部地形对沿主梁横桥向平均风速、风攻角、风偏角及桥梁跨中竖向风剖面等风特性的影响。研究了横桥向平均风速大小和风攻角之间的关系,定性讨论了存在风速放大效应的来流工况和桥址区地形特点之间的关系。结果表明:Y型沟谷桥址区风特性不同于一般的山区桥址区,当来流沿着几条比较顺直的沟谷时桥位处平均风速较大,其他风向桥位处风速较小;沟谷的弯曲致使沿着沟谷的来流产生回流和改向,这时桥位处的风攻角较大,沿着主梁的风偏角变化范围较大,水平风速较小,不存在风速峡谷放大效应;桥位处交汇的沟谷局部地形对桥梁跨中竖向风剖面影响较大。研究结果为桥梁设计风速的确定提供了依据,可为定性判断Y型沟谷口桥位处风特性提供指导。The wind field characteristics in complex mountainous areas are different from those in plain areas.The wind field is very complex and lacks a unified pattern,which has a significant impact on the structural vibration of large-span bridges.In order to study the influence of complex mountainous terrain on the wind field characteristics at bridge site,taking a cable-stayed bridge located at the intersection of several valleys as the engineering background.Based on ALOS digital elevation terrain model,the wind field characteristics at bridge site with different wind directions are calculated by CFD numerical simulation method.The influence of the main valleys at bridge site,and the local terrain at bridge site on the average wind speed,wind attack angle,wind deflection angle,and the vertical wind profile in the middle of bridge span along main beam is analyzed.The relationship between the average wind speed and the wind attack angle in the transverse direction of bridge is studied,and the relationship between the incoming flow conditions with wind speed amplification effect and the topographic characteristics of the bridge site is discussed qualitatively.The result shows that the wind characteristics at the Y-shaped valley bridge site are different from those at the general mountain bridge sites.When the incoming flow is along several relatively straight valleys,the average wind speed at bridge site is larger,and the wind speed at other wind directions is smaller.The bend of the valley results in the backflow and diversion of the incoming flow along the valley.In this case,the wind attack angle at the bridge site is large,the variation range of wind deflection angle along the main beam is relatively large,the horizontal wind speed is small,and there is no wind speed canyon amplification effect.The local topography of the valley at the intersection of bridge site has a great influence on the vertical wind profile in the middle of bridge span.The study result provides a basis for the determination of the design wind s

关 键 词：桥梁工程 风场特性 数值模拟 Y型沟谷 桥址区 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]