GREEN BAY, Wis. (AP) -- A support pier on a Wisconsin bridge sank after pilings underneath it buckled, probably because of corrosion.
That's the conclusion from a Wisconsin Department of Transportation investigation. The DOT has been working since last week to figure out what caused the support pier on the Leo Frigo Memorial Bridge to sink about 2 feet, creating a deep dip in the pavement.
The bridge that carries about 40,000 cars a day over the Fox River in Green Bay has been closed since Sept. 25.
The DOT said in a news release Thursday that investigators believe soil composition in the area and changes in the water table caused the corrosion. It says most other piers on the bridge are good condition. The agency will now begin working on a plan for repairs.
GREEN BAY, Wis. (WISCONSIN DEPARTMENT OF TRANSPORATION NEWS RELEASE) --The Wisconsin Department of Transportation (WisDOT) Northeast Region in Green Bay held a news conference today regarding the Leo Frigo (I-43) Bridge in Green Bay. Pier 22 on the bridge’s east side sank two feet on the morning of September 25, causing the deck to sag and the bridge to be closed to traffic indefinitely.
WisDOT noted at the news conference that the investigation is ongoing, but the bridge deck and Pier 22 appear to be in good shape. The inspection has revealed that pilings for Pier 22 that are located eight feet below the bottom of the concrete footing had buckled, apparently due to corrosion. The experts on the investigation team believe this corrosion was caused by a combination of the soil composition at this location and the rise and fall of the water table.
The investigation has also found that the vast majority of the other bridge piers being checked are in the same condition as they were when they were installed 33 years ago.
The bridge has not moved since it settled last week and the department believes there is no danger of collapse.
WisDOT’s NE Region Director Will Dorsey said, “As the investigation concludes, work will get underway to consider possible repairs. Our goal is to do whatever is needed to quickly and safely reopen the bridge.”
WisDOT has no estimate as to when the bridge might reopen.