Wind resistant design of long span suspension bridges with stay cable system

This paper presents the results of a series of numerical calculations of aerodynamic stability of very long span suspension bridges (main span 2,500 m) against flutter. In the progress, aerodynamic shape of girder was studied by spring supported wind tunnel tests first. Secondarily, aerodynamic stability of whole system of suspension bridge is investigated by numerical calculations (Direct FEM Flutter Analysis) using measured aerodynamic derivatives of the bridge girder. Besides, as a structural counteimeasure against flutter, the effects of Horizontal Stay Cables and Cross Stay Cables on it were evaluated. Finally, its setting position and length are discussed.