Improving the Wind Stability of Suspension Bridges during Construction

Abstract

The wind stability of suspension bridges in the construction phase can often be more problematic than in the final state. In this paper, numerical wind stability analyses are performed for the erection process of both state-of-the-art (the Höga Kusten Bridge) and hypothetical 3,000-m-span box-girder suspension bridges. Measures to improve the wind stability response in the erection phase are discussed. In particular, it is seen that the provision of an eccentric windward mass does not cause any significant improvement on the flutter stability limits for the analyzed case, but the selection of an alternative nonsymmetric erection sequence or the use of stationary aerodynamic appendages are seen to be more effective. Comparatively, assuming that the design wind speed for the construction stage is lower than for the final state, the response of the 3,000-m-span bridge is less problematic in the construction phase than in the final state.