Trends Summer 2016 | Page 10

Every year , selected bridges across the United States receive a tune-up : repainting , deck patching , repairing structural components that show wear . It ’ s routine .

That regular maintenance becomes less routine , however , when the bridge is one of the few routes over a major waterway , extends 1.5 miles , serves a region with a short construction season , and at 100-plus feet over the waterway , is subject to high winds .
Those were among the challenges the Wisconsin Department of Transportation ( WisDOT ) faced as the department considered how to best rehabilitate the Richard I . Bong Memorial Bridge , one of two bridges spanning the St . Louis River and Harbor to link Superior , Wisconsin , and Duluth , Minnesota . Ayres Associates designed the rehabilitation and provided the plans used by contractors over the two-year construction project .
It was a return “ home ” for Ayres . WisDOT designed the bridge ’ s steel tied arch span ; Ayres designed the rest of the structure . The bridge opened to traffic in October 1985 and is still one of the largest public works projects undertaken by the State of Wisconsin . But after serving the region for nearly 30 years , it needed maintenance .
“ There were deficiencies identified by our bridge engineer ,” said Matt Dickenson , the WisDOT project manager . “ The entire surface of the deck , over the course of salting the roadway for all those years , was showing some changes . The arch needed paint ; the paint only lasts so long . We were beginning to see some rust on components .”