Nonlinear aerostatic stability of a curved 275-m span suspension footbridge between Spain and Portugal

This study reports the nonlinear aerostatic stability studies carried out for a suspension footbridge with a curved deck spanning 275 meters over the Miño River between Spain and Portugal. The footbridge's aerostatic performance is controlled by its highly aesthetic but complex three-dimensional configuration, the high slenderness of the deck, the construction process, and the aerodynamic characteristics of the triangular 4.5-meter-wide bluff deck cross- section, which demands a detailed aerodynamic study. The analysis is conducted using a nonlinear modal-based method recently developed by the authors. The deck's rotation is driven not only by the aerodynamic moment-induced rotation but also by the drag-induced rotation due to the configuration of the cable supporting system and, very significantly, by the lift- induced rotation due to the deck's curvature.