GREEN BAY (WSAU-Wheeler News) Crews will begin stabilizing the Leo Frigo Memorial Bridge in Green Bay today, to keep it from sagging further before support piers can be checked and reinforced. The 51 concrete support piers were not anchored on limestone bedrock underground -- and some outside engineers say it might be why the bridge sank two-feet on September 25th.
D-O-T project manager Tom Buchholz tells the Green Bay Press-Gazette that designers do not always require support beams to touch the bedrock if the soil conditions are right. The bridge was built in 1980, and U-W Green Bay geologist John Luczaj said conditions that were safe then might have gotten worse. He said soil samples at the bridge uncovered loose sand and wet clay.
The D-O-T points to another problem as a possible cause -- corrosion around the pier that sank, which may have caused uncorroded beams to buckle. D-O-T regional bridge engineer Dale Weber says his engineers are confident that corrosion is the main cause. Still, he said soil conditions would also be studied -- and nothing will be left unexamined.
The Leo Frigo bridge in located north of downtown Green Bay on Interstate-43 over the Fox River. It's expected to be closed for at least a few more months.