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College Street bridge work under way
by Rick DeClue · News · July 30, 2015
Iowa Bridge & Culvert, L.C. of Washington, Iowa started repairs Monday on the College Street Bridge.
City administrator Matt Muckler said the goal is to have the bridge completely open before the Hoover Hometown Days celebration begins on Aug. 7, when other temporary street closures could disrupt city traffic.
At the July 20 city council meeting, the council was faced with a policy decision – spend current budget dollars to make a temporary fix to the bridge or keep it closed until it is replaced, which will take up to two years.
Larry Spellenberg of Veenstra & Kimm, the city’s engineering consultant, said the bid of approximately $15,000 would repair a “void” located under the approach pavement on the east side of the bridge. Steel piles on either side of the void would be connected by a steel cross-beam near the bridge’s existing cedar piles to form a strengthened enclosure for a concrete pour.
Muckler said the $15,000 will come from the Road and Street Budget as a maintenance item.
The repair is considered temporary since the bridge is scheduled for replacement in the next two years. Built in 1940 with a deck replacement in the 1980’s, the College Street Bridge is the only structure cited for replacement in the city’s bridge inspection reports. None of the West Branch’s other three inspected bridges are more than 37 years old or subject to substandard grades at this time. They each have a minimum remaining useful life of 20 years.
The new concrete is intended to provide a base to keep the east side approach stable. Spellenberg warned the council that there is some risk that pressure from the new concrete may force movement of the 75-year-old wooden piles supporting the bridge deck. Too much movement and the bridge would have to remain closed until it is replaced, he said.
On the other hand, he told the council, more expensive fixes to reduce this risk mean it might make more sense to wait for the replacement bridge anyway.
The weight limit for the bridge prior to its closure was 15 tons. Any movement after the repair is made will be monitored to determine whether that limit will need to be adjusted.
Muckler said most commercial truck traffic is currently using Fourth Street to Main Street. The city will talk to Cargill and other commercial interests regarding future weight limits and talk further with their drivers about using the bridge after it reopens.
A committee is being formed by the city to select a design consultant, subject to Iowa Department of Transportation approval, for the new bridge. Subsequent to that selection, the design and preconstruction work will take at least a year.
The bridge replacement is supported by a $1,000,000 “80/20” matching grant secured on behalf of the city by Veenstra & Kimm. Muckler said the city has $750,000 in its Capital Improvements plant to meet the 20-percent match requirements and cover additional improvements planned near the bridge and on Fourth Street.
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