考虑桥塔风场效应的斜拉桥抖振时域分析

与以往的抖振时域分析中仅模拟主梁风场不同,本文则同时模拟了主梁风场和桥塔风场,探讨了桥塔风场效应对主梁及桥塔抖振响应的影响,计算中采用了风洞中实测的紊流风速谱。空间相关性是影响桥梁抖振响应的一个重要因素,在杭州湾跨海大桥风洞试验中,对风洞空间相关性进行了测量研究,并在风场模拟时将衰减因子取为实测值。数值计算结果与风洞试验结果进行了对比,吻合较好,分析比较还表明:考虑桥塔抖振效应会显著增大桥塔的横桥向抖振响应,而对桥塔的顺桥向振动以及主梁振动影响不大。

TIME-DOMAIN BUFFETING ANALYSIS OF CABLE-STAYED BRIDGE CONSIDERING PYLON WIND FIELD

In previous time-domain analyses, only deck wind field was simulated. Both deck wind field and pylon wind field are simulated simultaneously. The influence of pylon wind field on buffeting responses of deck and pylon is discussed. The measured turbulence wind spectrums are used in the analysis of buffeting. Since spatial correlation is an important factor that influence buffeting responses, a study on spatial correlation of wind tunnel was carried out in the Hangzhou gulf wind tunnel test and the measured spatial correlation was used in simulation of wind field. The numerical results agree with those obtained from the wind tunnel test on the whole. The comparisons show that the effect of pylon wind field can increase the lateral buffeting responses of pylon significantly and contribute little to the buffeting responses of pylon along bridge and the vibration of main deck.