【摘要】 为了研究带悬挑人行道板流线型箱梁断面涡振性能,以某大跨悬索桥为工程背景,进行了涡振性能影响因素及气动优化措施的系列节段模型风洞试验。分析了来流攻角、检修轨道等对断面涡振性能的影响,研究移动检修轨道、附加轨道导流板以及底板竖直稳定板等气动措施的制振效果。结果表明此类断面对风攻角较为敏感,随攻角增大涡振性能逐渐变差,同时涡振幅值随阻尼增大呈非线性加速衰减趋势。检修轨道是此种断面形式的涡振敏感构件,检修轨道向箱梁底板中央移动能明显改善涡振性能;轨道附加导流板能进一步抑制涡振振幅,导流板越宽效果越明显;设置斜腹板导流板对改善所述的主梁断面的涡振性能效果不明显。更多还原

【Abstract】 A long-span suspension bridge using a streamlined box girder with a cantilevered walking slab was taken as an engineering example. Based on a series of section model wind tunnel tests,both the vortex induced vibration( VIV)performance of the main girder and the optimal aerodynamic measures were investigated. The influences of attack angle and guide vane on the VIV performance were analyzed. The aerodynamic measures controlling vibration suppression efficiencies were tested,including moving the maintenance rails,installing guide vanes with different forms. The research results indicated that the VIV performance is sensitive to wind attack angles,the VIV performance gradually gets worse with increase in wind attack angle,and the amplitudes of VIV reduce nonlinearly with increase in structure damping; the maintenance rails are the most sensitive element to VIV for this type of beam section,the movement of maintenance rails towards the centre of the undersurface of the box girder can improve the VIV performance effectively; the use of guide vane for maintenance rails can further mitigate the VIV amplitudes,and the wider the guide vane,the better the mitigation efficiency; furthermore,the guide vanes attached to the corner of inclined web and bottom plate are not suitable to improve the VIV performance.更多还原