Aerodynamic behaviour of cable stayed bridge Toyosato Ohhashi

This paper describes the aerodynamic behavior of a cable-stayed girder bridge . the wind tunnel experiment was conducted at relatively large Reynolds numbers by using a sectional model,which was 1/20 scale of a prototype.

The results show that the cable-stayed girder bridge witha trapezoidal closed crosssection is always stablea gainst a horizontal wind. However, some restricted motions could occur in an inclined wind to a horizontal direction with a comparatively low wind velocity and not so large amplitudes.

To make clear the aerodynamic behavior of the prototype in turbulent flow, the observation of atmospheric turbulences at the site where the prototype was constructed has been continued. By analyzing the structures in the atmospheric turbulence, it was recognized that the restricted motions,which had been observed in the wind tunnel experiment by using a smooth flow,would not occur in the prototype which was subjected to a natural wind fluctuating at random.