Experimental study on aerodynamic control of the vortex induced vibrations of a box girder with projecting slab

Abstract:

To seek an effective aerodynamic measure to control the vortex induced vibrations(VIV) of a box girder with projecting slab(BGPS),VIV of a 1∶50 scale sectional model with 10 cases were tested in TJ-1wind tunnel based on a cable-stayed bridge with composite box girder.The aerodynamic measures whose mitigation efficiencies were studied included moving the rails of tool car,installing guide vanes with different forms and installing spoilers with different forms.The research results show that VIV amplitudes of BGPS increase with the increasing of wind attack angle,so VIV performance is sensitive to wind attack angle.As for the guide vanes,they may raise VIV amplitude of BGPS,and the included angle and the width of horizontal board are key factors to affect mitigation efficiency of them,concretely,the bigger the included angle is and the wider the horizontal board is,the better the mitigation efficiency is.After the guide vanes are installed on BGPS,the rails of tool car have little effect on VIV performance of BGPS,so the mitigation efficiency of moving the rails of tool car is negligible.As for the spoilers,they can control VIV of BGPS efficiently,and the wider the spoilers are,the better the mitigation efficiency is,but the mitigation efficiency of the spoilers is correlative to wind attack angle closely.