Muskego Public Works Recommends Monitoring Bridge

City Engineer Dave Simpson laid out options for the Public Works Committee to consider regarding a bridge along Woods Road that is showing signs of deterioration.

"We received a report from an employee who is trained in bridge inspection, who noted that there is exposed rebar under the bridge," Simpson explained.  Salt water can leach through microcracks on the bridge deck's topside, which can corrode the metal bars and cause them to rust. In addition, certain girders in the structure were also showing signs of deteriorating.

Simpson said the bridge was constructed in the late 1960s and while concerned about the finding, he did not feel motorists were in imminent danger.  He explained that they reviewed three different options in addressing the problem.

Option one involved replacing the top four to six inches of the bridge deck, which would extend the life of the bridge by four to eight years at a cost of $80,000-$100,000.  The closure of the bridge would be three to four weeks.

A second option they reviewed was ruled out, Simpson said, as it involved replacing some of the girders while leaving others in tact.  "To have new girders positioned next to older ones just wasn't an option we wanted to consider."

The committee agreed that the third option would serve the city best, which involves increased monitoring of the bridge to every three months, with a professional inspector looking at the bridge once every year.  In addition, Simpson said a load rating calculation would be done to determine the maximum weight the bridge could sustain. Signs would be posted indicating how heavy trucks could be to use the bridge.

Simpson felt the increased inspections, along with sealing of the deck, would sustain the bridge for the next three years, which would allow for the completion of the Janesville Road project. 

"We didn't want to have two major thoroughfares closed at the same time," he said.  

The other benefit in waiting could also come from federal funding.  Should the load ratings reach a level of 50 percent of the bridge's original capability, Muskego would be eligible for 80 percent federal funding to replace the bridge.

Ultimately the committee approved the $1,400 expense that Simpson said it would take to perform the load rating calculations going forward.  Costs to replace the bridge in its entirety would then be a budget item for 2012.