Tuesday, January 23, 2018

I-43 over Fox River in Green Bay, WI

(Bridge Hunter (explains who Leo Frigo was), 3D Satellite)
The official name is the Leo Frigo Memorial Bridge (60+ photos).
Its initial name was Tower Drive Bridge.

(For my furture reference: swingbridge closed because a train is coming in the upper-right corner.)

This posting brought I-43 tied-steel arch bridge to my attention.
Jeff Rueckert posted
The last vessel in for the Season , Michigan Docked in Green Bay
[Judging from the power line towers, this tow is docked at the US Oil Fox River Terminal.]
"To comply with St. Lawrence Seaway standards, there is 120 feet of clearance under the bridge structure to the normal water level." [Bridge Hunter]

"Because of the bridge's height and slope, it is prone to being shut down during high wind warnings, heavy fog, blizzards, and icy conditions." [PayneAndDolan]

The approach spans to the steel-girder spans were concrete.
WebCam Snapshot
"Built 1981; closed Sept. 25, 2013, after the deck was found to be sagging; reopened January 5, 2014" [Bridge Hunter]

[Pier 22 sank two feet.]

[A dramatic demonstration of the flexibility of steel. But I'm surprised the decking didn't crack.]
There are three videos at the end if you want to listen instead of read. I found them before I finally found some reports on the problem and fix.
Industrial byproducts [e.g. fly ash because this area was old fill], highly corrosive black, powdery material in the soil, caused some underground steel supports to corrode and buckle under the weight of one bridge pier. A state investigation found that pilings under four other nearby piers had also corroded. Repairs to the bridge began in November 2013 and focused on hoisting up the sunken section of the bridge while neutralizing the corroded sup-ports. Crews installed deep, concrete shafts underground that, instead of the pilings, support the weight of the piers. Before this, a $1.6 million project built two steel support towers to prop up the bridge and prevent it from sinking further.
The bridge was closed for three and a half months for repairs, with a bill of $18-20 million. The Federal Highway Administration approved emergency funding for the repairs, which covered most of that cost. It was reopened in January 2014, but crews will perform additional preventive maintenance and other work in the spring and summer. The estimated impact of closing the Leo Frigo Bridge was $139,000 a day (approximately $14.5 million). 
"In winning the project, Payne & Dolan faced penalties of $50,000-a-day for a delayed reopening. The repair project solution involved erecting two temporary towers to prevent the bridge from sagging further and ensure worker safety while performing permanent repairs to the bridge. Payne & Dolan then placed new pilings at the bases of piers 21 to 25. Next the approximately 1,600 ton superstructure was moved back into place via hydraulic jacking.  The project was completed in time to allow the bridge to be opened to traffic two weeks ahead of schedule on January 5th, 2014; just in time to accommodate a sold-out crowd heading to Lambeau Field to watch the Green Bay Packers face the San Francisco 49ers in the NFC wild-card playoff." [PayneAndDolan]


Within the report WisDOT explains their analysis and repairs. Determining old industrial soils used as fill, such as fly ash, corroded steel pilings causing pier 22 to buckle. Engineers determining five supports in all were surrounded by the soil requiring extensive repairs to them all.

"We put four concrete foundations down into rock - tied existing pier into those posts and solidified the foundations," said Buchholz.
Buchholz says the repairs provide corrosion protection for 75 years.  A near tragedy caused by corrosive fills that based on this document transportation engineers will now be more wary of.
"The soil showed fly ash fill,  but we never asked was it corrosive or not corrosive," said Buchholz. "What this shows is now we need to be asking those questions when you run into fly ash fill."
The report also tells how WisDOT installed corrosion monitoring equipment at eight sites on both sides of the Fox River that will be checked every two years.
Final cost of project $15 million.
NACE has links to the 3000 page final report. Fortunately, the report starts with a 3 page executive summary.
Final Report, Part I, page 2 of the Executive Summary

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(new window) (Includes diesel pile driver action.)

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