带悬臂流线型箱梁大比例节段模型涡振试验研究

Experimental Study of Large Scale Sectional Model for Vortex-Induced Vibration of Streamlined Box Girder with Cantilever Walk Slabs

大比例节段模型风洞试验是预测大跨度桥梁主梁涡振性能的有效方法之一。为研究带悬臂流线型箱梁涡振性能影响因素及气动优化措施,以某大跨悬索桥为工程背景,进行了1∶25大比例节段模型风洞试验。试验研究了不同来流攻角状态下主梁断面的涡振性能,并检验了移动检修轨道位置、安装悬臂、轨道导流板以及底板竖直稳定板等气动措施的制振效果。研究结果表明:随攻角由负变正,断面的扭转涡振性能逐渐变差;检修轨道向底板中央移动能有效降低涡振振幅,同时在检修轨上附加导流板能进一步地优化涡振性能,并且导流板越宽效果越明显;悬挑臂导流板以及底板设竖直中央稳定板不适于提高本文主梁断面涡振性能。

The wind tunnel test of large scale sectional model is one of the effective ways to ortex-induced vibration （VIV） performance of the main girder of long span bridge. nfluential factors and the optimized aerodynamic measures for the VIV performance of the streamlined box girder with cantilever walk slabs, a long span suspension bridge was cited as an example and the wind tunnel tests of the 1 ： 25 large scale sectional model were carried out. The VIV performance of the cross section of the main girder under the different wind attack an- gles was experimentally studied and the effect of vibration suppression of the different aerody- namic measures including the positions of the movable maintenance rails and the installed cantile- vers, guide vanes on the rails and vertical stable plates at the bottom plate were checked. The re- sults of the study demonstrate that with the changing of the attack angles from the negative to the positive, the torsional VIV performance of the cross section of the main girder gradually becomes worse. The moving of the maintenance rails towards the centre of the bottom plate can effectively decrease the VIV amplitude. At the same time, the installing of the guide vanes on the mainte- nance rails can further optimize the VIV performance and the wider a guide vane is, the effect of vibration suppression will be more effective. The installing of the guide vanes on the cantilevers and the vertical central stable plates at the bottom plate is not suitable to improve the VIV per- formance of the cross section as described in this study.