BRIDGES: Investigation reveals cause of dip in Wis. bridge

After a week of investigating, officials believe they now know why a section of the Leo Frigo Memorial Bridge in Green Bay suddenly dipped on Sept. 25.

The Wisconsin Department of Transportation (WisDOT) said corrosion of steel pilings below a support pier created the buckle. The 100-ft-long pilings weakened due to a combination of water and the composition of soil surrounding the bridge support. Fill on the east side of the bridge is comprised of materials like foundry sand.

“This does not indicate the rest of the bridge is in danger of collapse,” Tom Bucholz, WisDOT project manager, told the Press-Gazette. “These foundations, these piles, have huge safety factors on them so if one pile fails there are 39 others to support the bridge.”

There are a total of 51 support piers on the 8,000-ft-long span, and while an analysis is being conducted officials believe the other 50 are in relatively good shape.

WisDOT, however, is not sure yet how it will repair the bridge, which is the second longest in the state.