State Road 414 Bridge

Orlando, Florida, USA

4 x 135 kg Tuned Mass Dampers

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This bridge extends a road over a highway just north of Orlando, Florida. The bridge features architectural (not structural) double arches, which run the length of its span. Motorists began to report that the bridge’s distinctive arches were visibly moving in light winds. Designers wanted to mitigate this movement without destroying the arches’ aesthetic impact. Any damping solution would, like the rest of the bridge, need to be resilient to Florida’s hurricane-prone climate. We developed a set of tuned mass dampers (TMDs) that would sit inconspicuously between the double arches. Each TMD contained a leaf spring: composed of a fixed centre affixed to the bridge arches and two flexible ends that each hold two 150-pound weights. When the wind begins to act on the arches, the weights suspended from the wings offer passive resistance, dissipating the wind’s energy while limited the arches’ movement.