Aerodynamic drag force on bridge deck in a large-scale along-wind velocity fluctuation

Abstract

This paper sets two main objectives which are the generation of large-scale along-wind velocity fluctuation and the evaluation of the aerodynamic admittance function for the 2nd Jin-do bridge for comparison with the Davenport function. For the first objective, to generate large-scale along-wind velocity fluctuation, it is important to set the appropriate target wind properties. These properties are commonly determined by field instrumentation data or the target of the experiment. Using the active turbulence generator, it is experimentally verified that the relationship between the angle of the wing plate and the amplitude of the along-wind velocity fluctuation is linear. At the first trial, measured wind velocity fluctuation is not similar with the target spectrum density. Therefore, to match the generated wind to the target, trial and error method is selected to compensate the shortage. As for the second objective which is the evaluation of the aerodynamic admittance function for 2nd Jin-do bridge and comparing it with the Davenport function, the aerodynamic admittance function value of the 2nd Jin-do bridge is around 50~60% of Davenport value for a 10% turbulence intensity and a large-scale turbulence length experiment.