SOLVING Problems and BUILDING Value
Sheridan County, WY
Sheridan County needed to replace and upgrade a 92-year old bridge that was structurally deficient. WWC was retained to evaluate alternatives for replacement of the existing bridge, design the selected alternative, provide bid documents for construction, and serve as construction engineer for surveying, inspection, and monitoring during construction.
Cost considerations for a new bridge are a very important aspect since new bridge structures are typically very expensive. After completion of the hydraulic analysis, preliminary design, and cost studies, a prefabricated, 100’ single span steel bridge was selected that was designed to pass a peak discharge of about 9,800 cfs with high debris & ice potential. The new bridge is totally contained, with corrugated steel bin wall abutments behind driven “H” pile support structure. The pre-fabricated bridge structure saved the County over $100,000 over a conventional bridge structure.
Due to previous ice & debris damage to existing bridge, WWC designed a unique ice rail system to protect the support piles from potential damage during high spring flows.
The design incorporated special provisions for removal of the existing bridge in one piece including the deck to preserve the historic structure.