How can aerodynamic bridge design help a bridge withstand cyclones?

Aerodynamic bridge design is essential for ensuring that structures can withstand the intense forces of tropical cyclones. The primary goal of this design approach is to minimize the amount of solid material facing the wind, allowing air to pass through or around the bridge without triggering dangerous oscillations.1

Engineers achieve this through several key strategies:

• Open Trusses: By utilizing open trusses for the deck rather than solid steel plates, designers allow wind to pass through the structure, preventing the buildup of pressure that can lead to failure.2
• Aerodynamic Shaping: Some bridges, such as the Severn Bridge, use shallow steel boxes shaped to deflect wind over and under the deck, similar to how a cutwater directs water around a pier.2
• Damping Systems: Inclined suspenders can be used to dampen longitudinal and vertical movements, which helps stabilize the bridge when it begins to oscillate during heavy winds.2

These measures are critical because, without proper aerodynamic consideration, wind can induce vertical and torsional (twisting) motions that may cause a bridge to collapse.13