四翼箱梁三分力系数与断面优化数值研究  

Numerical Study on Static Coefficients and Section Optimization of Four-flange Box Girder

作　　者：宁立 梁余定 沈炼 王文赞 封周权[3,4,5] Ning Li;Liang Yuding;Shen Lian;Wang Wenzan;Feng Zhouquan(Guangdong Communication Planning&Design Institute Co.,Ltd.,Guangzhou 510507,China;School of Civil Engineering,Changsha University,Changsha 410022;College of Civil Engineering,Hunan University,Changsha 410082,China;Key Laboratory for Wind and Bridge Engineering of Hunan Province,Hunan University,Changsha 410082,China;Chongqing Research Institute of Hunan University,Chongqing 401133,China)

机构地区：[1]广东省交通规划设计研究院集团股份有限公司,广东广州510507 [2]长沙学院土木工程学院,湖南长沙410082 [3]湖南大学土木工程学院,湖南长沙410022 [4]湖南大学风工程与桥梁工程湖南省重点实验室,湖南长沙410082 [5]湖南大学重庆研究院,重庆401133

出　　处：《市政技术》2021年第11期48-53,共6页Journal of Municipal Technology

摘　　要：普通混凝土箱梁一般仅有两侧上翼缘,而某些桥梁为了设置较宽的人行道,会在混凝土底板附近两侧各设置1段外伸钢挑臂,从而变成"四翼箱梁"。为揭示四翼箱梁静三分力系数特征,基于计算流体动力学(CFD)对某矮塔斜拉桥四翼缘主梁典型断面的静三分力系数进行了分析,并提出了其主梁断面的优化方案。研究结论显示:四翼缘主梁成桥状态阻力系数要明显大于施工状态时的系数,阻力系数随风攻角的变化大致呈V字形变化,而升力系数与扭矩系数随风攻角的增大而逐渐增加;下翼缘人行道板镂空方案相比实腹方案的扭矩减小明显,在±15°风攻角下扭矩分别减小9.1%和49.8%。该研究结论可供同类桥梁抗风设计提供参考。Ordinary concrete box girder generally has only two upper flanges on both sides.For widening the side walk,one section of extended steel cantilevers are sometime set on each side near the concrete floor to become a"fourflange box girder".In order to explain the characteristics of aerostatic coefficients of concrete four-flange box girder,this paper analyzes the aerostatic forces of the typical section of four-flange main girder of a extrodosed cable-stayed bridge based on computational fluid dynamics(CFD).Meanwhile,the optimization scheme is proposed.The results show that the drag coefficient of the four-flange main girder in completion stage is significantly larger than that in the construction stage.The drag coefficient distribution is roughly V-shaped with changes of wind attack angles.Both the lift coefficient and torque coefficient gradually increase with the increase of the wind attack angle.Compared with the full solid scheme,the torque of the lower flange with hollowing pavement slab is significantly reduced by 9.1%and 49.8% at positive and negative 15°wind attack angle respectively.The conclusion provides reference for wind resistant design of similar bridges.

关 键 词：四翼箱梁 数值模拟 扭矩 静力三分力系数 断面优化 

分 类 号：U448.213[建筑科学—桥梁与隧道工程] U441[交通运输工程—道路与铁道工程]