In 2011, Tropical Storm Irene damaged communities across Vermont like no other storm before. During recovery, our team evaluated several state owned rail lines, including bridges.
While inspecting Bridge 501 over the White River, we noticed severe scour damage to its south pier. The pier had dropped nearly six feet and shifted nearly five feet, twisting the superstructure within inches of collapse. Recognizing the crisis, we jumped into action, calling in our structural, geotechnical and hydraulic engineers along with our construction managers to rescue the bridge.
With the entire region in a state of emergency, resources were spread thin. We worked around the clock to figure out how best to use the materials at hand, stabilizing the slipping bearings with rapid set concrete and splicing together the girders with salvaged highway bridge beams and high strength cables. Working in lock step with the contractor, we designed the shoring towers to be offset from the pier and retrofitted the girders to work as a hinged cantilever over the sunken pier.
The intense effort didn’t stop until rail service was restored and work toward replacing the damaged pier could begin.