3D Nonlinear Aerostatic Stability Analysis for Suspension Bridges with Ultra-Long Span

Abstract

With the rapid increase of span length, suspension bridges are becoming lighter, more flexible, and lower damping, which result in more and more sensitive to wind actions, in particular related to aerostatic and aerodynamic instability. The intrinsic limit of span length due to aerodynamic flutter stability seems to be about 1,500m for a traditional suspension bridge, but both twin and triple box stiffening girders could provide a 5,000m suspension bridge with high enough critical flutter speed. Three-dimensional nonlinear aerostatic stability analysis has been performed on the suspension bridges with single and multi-box girders having ultralong spans from 1,500m to 5,000m. It can be concluded that the single and the multi-box girders can support a 1,500m and 5,000m spanned suspension bridge with high enough aerostatic critical speed, which can meet with the requirement of strong wind.