How can wind loads influence gusset plate connections in long-span truss bridges under certain conditions?

• A. Wind-induced dynamic effects (flutter/torsion) can amplify stresses at connections, accelerating fatigue and potential joint failure.
• B. Wind has no effect on gusset plate connections in long-span truss bridges.
• C. Wind only affects the deck, not connections.
• D. Wind reduces stresses on connections over time.

Answer: (C)

Wind loads can have a direct and significant impact on gusset plate connections through aeroelastic and dynamic effects. In long-span trusses, gusset plates transfer forces from multiple members, so when wind excites the structure, dynamic forces such as flutter, torsion, and buffeting can be transmitted right into these joints. This can raise the stress ranges in bolts, welds, and the plate itself, accelerating fatigue and increasing the potential for joint failure under gusty or turbulent winds. The fluctuating pressures from wind cause cyclic loading at the connections, which is especially critical if the structure’s natural modes are excited or if detailing is not robust. So wind influence is not limited to the deck; it can drive significant demands at gusset plate connections, and it does not typically reduce stresses over time.