Effect of Turbulence Intensity and Length Scale on Vortex-Induced Vibration of Parallel Cable-Stayed Bridges

Abstract

In this study, the target turbulence length and turbulence intensity were generated by using active turbulence generator device and turbulence grid. The study carried out about the effect of the generated turbulent wind on vortex-induced vibration of parallel cable-stayed bridges. The developed active turbulence generator consists of aerofoil and flat gust. Two wing plates can control vertical and along-wind turbulent winds respectively. The relationship between the turbulent wind velocity and the wing motion was experimentally derived and the turbulence was simultaneously achieved by independently controlling each wing. Turbulent wind satisfied vertical and along-wind von karman spectrum at the same time. In order to verify the effects of turbulence length scale and intensity on the response to parallel bridges, three of the four variables (along-wind turbulence intensity, along-wind turbulence length scale, vertical turbulence intensity, vertical turbulence length scale) were used as control variables and the other one was used as a dependent variable. To verify whether the experimental results are characteristic of parallel bridge or not, compared response between single bridge test and parallel bridge test. Among the variables, turbulence intensity was main factor in the amplitude response about parallel bridge section model. However, turbulence length scale was not main factor to response of bridge model.