By Kevin Jump, PE – City of Sheboygan Engineering Division
The rehabilitation of the 8th Street Bridge over the Sheboygan River is nearing completion. The current bridge was constructed in 1995 for a cost of $7.3 million and received the 1996 Bridge Award for Movable Spans from the American Institute of Steel Construction. Teng & Associates, Inc. of Chicago designed the bridge and Lunda Construction Co. of Blackriver Falls, WI was the General Contractor. The bridge is an unbalanced bascule bridge with no counterweights to aid in the lifting of the bridge. The bridge was a state-of-the-art design that was also patented by the designer. This specialized design was chosen, in part, to eliminate excavation in a river bed that was identified as a US EPA Superfund site.
In November 2014, the City of Sheboygan entered into a State Municipal Agreement with the Wisconsin Department of Transportation for the painting of the exterior steel supports and to repair the S. 8th Street concrete approaches to the bridge. The estimated construction cost was $170,250. Federal/State funds would have covered $136,200 with the remaining $34,050 being the City of Sheboygan’s cost.
During the analysis of the bridge it was determined that there was excessive corrosion to the bridge girders, bearings, beams, and hydraulics. Once the analysis was completed it was determined several of the bridge’s components needed to be refurbished or replaced. This project became much more than an exterior painting project. A new State Municipal Agreement between the Wisconsin Department of Transportation and the City of Sheboygan had to be drafted and was signed in April 2016. The new estimated construction cost to make all repairs to the bridge was $3,222,628. Federal/State funds covered $2,578,102 of this cost with the remaining $644,526 being the City of Sheboygan’s cost.
In 2016, AECOM of Milwaukee began design of the rehabilitation, with the design being completed in the spring of 2017, followed by bidding the project. Fickett Structural Solutions, Inc. of Middleton, WI was selected to provide onsite construction oversight and inspection of the work on the bridge.
During the summer of 2017, Drax Inc. was awarded a $2,377,000 contract for the work on the bridge. Construction started in September 2017 with bridge painting and concrete repairs. In November, repairs and maintenance to the hydraulic equipment began, this included Drax Inc. removing the four large hydraulic cylinders, each weighing 27,000 pounds. The cylinders were then shipped to Michigan to be inspected and rehabilitated. During the inspection process it was determined that bearings that connect each cylinder to the bridge would also need to be replaced. This required that four 4,000-pound pins also be removed from the bridge and shipped to Michigan to be inspected, rehabilitated, and to verify that all the components would fit together when reassembled in the bridge. The additional costs were not unexpected in the construction cost estimates.
In March of this year, work began to reassemble the hydraulic components of the bridge. This included reinstalling the pins and hydraulic cylinders, installing new hydraulic hoses, and replacing 2,200 gallons of hydraulic fluid.
By the middle of April, the hydraulic system was completely reassembled and ready for final testing. With testing recently completed the bridge is again ready for several more years of service.
When all work is completed, the final cost for repairs will be approximately $2,750,000. As an unbalanced bascule bridge with no counterweights, this type of bridge requires more frequent maintenance and repairs than a conventional counterweight bridge. The 8th Street Bridge was 22 years old when this restoration project began, whereas conventional counterweight bridges are expected to have a 40-year span before needing to be rebuilt.