Ayres provided design engineering services for the replacement of the Plum Creek bridge and approaches on USH 10 in Pierce County, Wisconsin. This project was unusual because the chosen alternative involved a shorter, single-span bridge in place of the existing five-span bridge built in the 1950s.
Hydraulic analysis showed the old structure was larger than it needed to be. A two-span replacement bridge was considered, but the single-span design saved about $165,000, shortened the construction time by about three weeks, and improved the hydraulics for flow under the bridge because of the lack of piers.
A temporary traffic bypass and bridge were constructed to avoid inconveniencing residents with a detour during construction.
Challenges included designing the span’s horizontal curve, making sure the new bridge provided sufficient clearance for a snowmobile trail underneath, and carefully working above and around an environmentally sensitive creek, including investigating debris capture systems for the main span.