Abstract
In recent years, innovation of the bridge technology in Japan is remarkable. Especially, the number of bridge construction of the cable-stayed bridge is increasing every year from short span bridge less than 100m to long span bridge longer than 800m, because the cable-stayed bridge has both structural and aesthetic advantages. However, since the cable-stayed bridge has lower stiffness, the vibration problem easily occurs in the wind that induces vortex-excited vibration, galloping and flutter. Until now, in the girder cross section with open deck section and two-box girder, experimental investigations have been carried out about the influence of shape of fairing and shape of box girder on aerodynamic instability. But there are few examples of investigation about influence of cavity under deck of two-box girder on aerodynamic instability. Therefore, the present paper treats the influence of cavity under deck of two-box girder bridge on aerodynamic instability.
