The Study Of The Effect Of Model’s Aspect Ratio On Bridge Wind Tunnel Test

With the modern bridge span records continue to be refreshed, the structures tend to begentle and the damping reduces, the wind load becomes the controlling factor of bridge design.Wind tunnel tests play a vital role in the structural wind engineering, the choice of windtunnel test methods directly affects the accuracy of test result. The proper model should beselected based on the structure feature, then develop the best optimal test program. Windtunnel tests have limitations, the width of the wind tunnel limits the length of the model, it isnecessary to make further study about the model aspect ratio, in order to improve thereliability of the test analysis.This paper takes Gangzhu’ao Bridge and the scecend Humen Bridge-NizhoushuidaoBridge as engineering background. In the premise of the same scale ratio of the model withreal bridge, the influence of different aspect ratio to test result is researched. Dividing theGangzhu’ao Bridge into two operating conditions as with railings(complete state) and withoutrailings(construction state), the aspect ratio of the three models are as follows:1.2,1.9,2.8;Nizhoushuidao Bridge divided into model with end plates and model without endplates, the aspect ratios of the two models are as follows:1.9,3.8. The main contents of thestudy are as follows:(1) The mean wind pressure coefficient and the fluctuating pressure coefficient ofGangzhu’ao Bridge’s models with three different aspect ratio and Nizhoushuidao Bridge’smodels with two different aspect ratios were compared.(2) The static aerodynamic coefficient of Gangzhu’ao Bridge’s models with threedifferent aspect ratio and Nizhoushuidao Bridge’s models with two different aspect ratioswere compared.