Suspension Bridge Effects

Suspension bridges, susceptible to strong winds, can produce a torsion effect.

A suspension bridge refers to a bridge with a load-bearing deck hung by suspension cables on vertical suspenders. Suspension bridges, vulnerable to environmental and structural forces, can suffer certain effects, or strains on their infrastructure.

Support Cables

Suspension bridges rely on cables to support the load of the deck. Any load, or weight applied on, and across, the bridge span converts into tension absorbed into the main cables. Cables offer elasticity, or enable some bridge movement to absorb shock caused by the bridge's live load.

Live Load

Suspension bridge live load refers to such dynamic forces as traffic, precipitation, temperature changes and wind. Wind gusts in particular tax suspension bridge elasticity. Lateral winds acting on the bridge can lead to a dangerous torsion effect.

Torsion Effect

The torsion effect refers to bridge oscillation. Winds trigger bridge flexing, or oscillating movement, which in turn serves to increase the amount of contact the wind has with the bridge's surfaces. This creates the torsion effect, or an actual twisting motion, across the bridge span.

References

• PBS: Suspension Bridge
• "History of the Modern Suspension Bridge: Solving the Dilemma between Economy and Stiffness"; Tadaki Kawada; 2010

Resources

• "Suspension Bridges and Cantilevers"; D. B. Steinman; 2009