Wind tunnel test for vortex-induced vibration of vehicle-bridge system section model

摘要

Vortex-induced vibration of bridges happens at a relatively low wind speed and while vehicles often run on a bridge at that wind speed. Thus, it is necessary to study how the vehicles influence vortex-induced vibration of vehicle-bridge systems. Based on the project of Shanghai Bridge over Yangtse River, the wind tunnel test for vortex-induced vibrations of vehicle-bridge system of a 1:60 model is presented. The wind tunnel test is introduced in detail including the equipments, test procedures and discussion of results. The results show that the vehicles have much influence on vortex-induced vibration of vehicle-bridge system for the Shanghai Bridge over Yangtse River. With speed increasing, the displacement of the bridge with vehicles fluctuates larger than that of the bridge without vehicles. The frequencies of vibration could be divided into three stages, vertical vibration frequency for the first stage, torsional vibration frequency for the second stage, and suspension system vibration frequency for the third stage. For the bridge with vehicles, vertical vortex-induced vibration was accompanied with torsional vibration and the frequencies of the two vibrations are equal. The displacement of vortex-induced vibration for the bridge with vehicles was larger than that of vortex-induced vibration for the bridge without vehicles. Due to the disturbance of vehicles, the lock-in wind speed region of the vortex-induced vibration appears ahead.