斜拉桥非规则索塔自立状态风振试验研究

Experimental Study on Wind-induced Vibration of Free-standing Irregular Pylon of Cable-stayed Bridge

摘要:

为研究大跨度斜拉桥非规则索塔在自立状态下不同风向角的风致振动性能，选取一座跨度为480 m的双索面斜拉桥为工程背景，通过缩尺比为1∶60的气弹模型风洞试验，测量了均匀流场、紊流场中桥塔自立状态下的风致振动响应。试验结果表明：桥塔在驰振检验风速范围内不会发生驰振现象，在0°、3°、5°、10°风向角下会发生显著的顺桥向涡激振动，在紊流场中桥塔抖振响应随风速增加而增大，顺桥向抖振响应大于横桥向抖振响应。此外通过计算塔顶位置的运动加速度，评估了桥塔自立状态下施工人员的舒适性指标，结果表明：塔顶最大运动加速为0.26 m/s²，舒适性指标满足中国规范要求。

Abstract:

In order to study the wind-induced vibration performance of free-standing irregular pylon of long-span cable-stayed bridge at different wind angles, a double-plane cable-stayed bridge with a span of 480 m is selected as the engineering background. The wind-induced vibration response of the free-standing bridge pylon in uniform flow field and turbulent flow field is measured by the aeroelastic model wind tunnel test with scale ratio of 1∶60. The test results show that the galloping phenomenon will not occur in the galloping test wind speed range of the bridge pylon, and the significant forward bridge vortex-induced vibration will occur at the wind angles of 0°, 3°, 5° and 10°. In the turbulence flow field, the buffeting response of the bridge pylon increases with the increase of wind speed, and the forward bridge buffeting response is greater than the cross bridge buffeting response. In addition, the comfort indexes of the construction personnel are evaluated at the free-standing bridge pylon state by calculating the motion acceleration at the top of the pylon. The results show that the maximum motion acceleration of the pylon top is 0.26 m/s², and the comfort indexes meet the requirements of Chinese specifications.