Aerodynamic stability of self-anchored double deck suspension bridge

In this paper wind tunnel test results and their interpretations, which were performed to study the aerodynamic stability of a self-anchored double deck suspension bridge, are presented. Section, tower and full models were tested under smooth and turbulent flow conditions. Even though the drag coefficient of the girder had high value, the amplitude of the lateral vibration was found to be very low. This may be due to the restraint provided by the horizontal curvature of the cables. Because the two natural frequencies of the tower, out-of-plane bending and torsional, were not well separated, coupled motions were observed in a wide range of wind velocity. It has to be emphasized that the vibration characteristics of the tower in the self-anchored suspension bridge may be very sensitive to the longitudinal boundary conditions of the girder at the supports. The effectiveness of corner cut, countermeasure to reduce the tower vibrations, was also studied.