Advanced Dynamic Wind Load Analysis of Ultra Long Span Suspension Bridges

Abstract

Ultra-long-span suspension bridges are highly flexible, lightly damped, prestressedstructural systems whose dynamic response is strongly governed by the interactionbetween atmospheric turbulence, structural motion, and unsteady aerodynamicforces. For very large main spans, wind loading cannot be represented adequately bya static pressure distribution. The bridge must be treated as a nonlinear aeroelasticsystem in which displacement, velocity, torsional rotation, cable tension, and wakedevelopment interact continuously.This paper presents an advanced theoretical and computational framework forthe analysis of wind-induced response in ultra-long-span suspension bridges. Theprincipal phenomena considered are aerostatic deformation, turbulent buffeting,vortex-induced vibration, galloping, torsional instability, and multimode flutter. Theformulation combines nonlinear structural mechanics, prestressed cable theory, finiteelement analysis, stochastic wind modelling, unsteady aerodynamics, state-space aeroelasticity, computational fluid dynamics, reduced-order modelling, and structuralcontrol.