深切峡谷桥址区风场空间分布特性的数值模拟研究  

Study of spatial distribution feature of wind fields over bridge site with a deep-cutting gorge using numerical simulation

作　　者：李永乐[1] 蔡宪棠[1] 唐康[1] 廖海黎[1] 

机构地区：[1]西南交通大学,四川成都610031

出　　处：《土木工程学报》2011年第2期116-122,共7页China Civil Engineering Journal

基　　金：国家自然科学基(90915006);教育部新世纪优秀人才支持计划(NCET-06-0802);四川省杰出青年学科带头人计划(2009-15-406)

摘　　要：以大跨度山区悬索桥为工程背景,针对深切峡谷桥址区复杂的地形地貌,应用CFD商业软件FLUENT进行区域地形风场数值模拟分析,通过多工况的计算分析,揭示了复杂地形地貌桥址区空间风场的分布特征,对比分析桥址区风速沿竖向和沿主梁方向的变化特点,确定不同攻角情况下桥面风速及其与梯度风速的比值关系,并根据风洞试验及风致响应分析的需要,提出以包络线表示的风速-风攻角对应关系。研究表明,深切峡谷桥址区风场特性复杂,具有明显的三维特征,与跨海及跨江大桥桥址区的风场特性存在明显差异。研究结论为桥梁设计风速确定及进一步的抗风设计提供依据。A long-span suspension bridge over a deep-cutting gorge in mountain area is employed as a typical example.Numerical simulation of the wind field distribution of the bridge site with complex terrain is carried out by employing CFD commercial software FLUENT.According to the calculation analyses of different cases,the spatial distribution feature of the wind field over the bridge site with complex terrain is explored,and the variations of wind velocities along the vertical direction and along the bridge deck are obtained.Furthermore the ratios of the wind velocity at the height of bridge deck to the gradient velocity are calculated for different attack angles.According to the requirements of both wind tunnel test and the analysis of wind-induced responses,an envelope curve is presented to address the corresponding relation between wind speed and wind attack angle.It is shown that the wind field at mountain bridge site is essentially different from that near the sea or over a wide river,and it is very complex with particular spatial ambient flow.The research conclusions provide a basis for the determination of design wind speed of the bridge.

关 键 词：大跨度桥梁 复杂地形 桥址区 风场特性 计算流体动力学 

分 类 号：U442.59[建筑科学—桥梁与隧道工程]