Engineers with the state Department of Transportation say they have found the cause of the sag in an interstate bridge in Green Bay.
The Leo Frigo Bridge has been closed for more than a week. The bridge spans the Fox River where it meets Green Bay. It's been closed since a two-foot sag on a portion of the bridge was discovered last week.
Since then, DOT engineers have excavated the pier that gave way, and discovered a piling that buckled. Tom Buchholz, the Leo Frigo project manager, says the failure was due to severe corrosion where the concrete pier meets metal pilings sunken deeply underground.
Buchholz's team is also examining nearby support pilings, where it “did see corrosion.”
“Not to the severity obviously that caused failure, but you could see corrosion,” says Buchholz. “I want to reiterate that this does not indicate that the rest of the bridge is in danger of collapse.“
The DOT is not planning to do extensive excavation on all of the bridge's 51 supports. The bridge was finished in 1980.
Buchholz says the concrete piers go down 15 feet where they meet the metal pilings which are embedded 100 feet below ground. Buchholz says that the cause of the corrosion could be “fill material that has been in place prior to construction and a combination of groundwater interacting with that soil.“
The DOT is still not predicting when the bridge may open to traffic. Officials say the project is not impacted by the federal government's shutdown.
