Abstract
In this paper, the relation between the critical wind speed of coupled flutter Vs estimated by Selberg's formula and some structural elements of a truss stiffened suspension bridge was studied. It was clarified that the increase in lateral members' section, diagonal members' section and truss height effectively improves Vs without much additional cable weight.
Some very long span suspension bridges whose main span range from 2000m to 3500m were designed and approximate weight of those bridges was estimated. As the result, it was found that such a suspension bridge with 2000m-2500m main span can be constructed by enlarging the above-mentioned members which increase torsional rigidity of the truss girder.
