Aerodynamics of two edge girders for long-span cable-stayed bridges

The aim of this study is to obtain a series of fundamental data on aerodynamic characteristics of two edge girders, such as Butter instability and vortex-induced vibration. Two edge girders have, in general, structural and economical advantages for long span cable-stayed bridges. The effect of geometrical shape of girders, their location and incidence angle of flow on the two-edge girders aerodynamics was investigated by a series of wind tunnel tests. Aerodynamic derivatives, associated with Butter instability, are obtained by IDOF heaving/torsional forced vibration method. Furthermore, Flutter mechanism is investigated by unsteady pressure measurement under IDOF heaving/torsional forced vibration.