GREEN BAY, WI (WTAQ) - The Wisconsin Department of Transportation says a combination of water and soil is to blame for piling corrosion involving a settled pier that caused the I-43 Leo Frigo Memorial Bridge to dip last Wednesday.
The bridge remains indefinitely closed after a double hammer head pier settled 22 inches on one side and 27 inches on the other.
Officials believe the corrosion was caused by a combination of the soil composition and the rise and fall of the water table. Pier 22 buckled due to the corrosion.
Testing around adjacent piers 21, 23 and 25 on the span’s eastside found similar corrosion issues involving the steel pilings that driven 100 feet below ground.
WisDOT says soil samples indicate the corrosion is near the surface and involves fill dirt that is unique to the area.
There are a total of 51 supporting piers.
WisDOT says piling failings is something you don’t hear about and can’t think of another instance like this.
WisDOT spokesman Kim Rudot couldn’t say at this point whether settled pier 22 or three others would have to be completely replaced.
At this point there is no timeline for the bridge to be repaired, how much it will cost or who will pay for it.