| Connect Follow us on Twitter Like us on Facebook
About | Subscribe | Advertise


Download our free e-book! Protecting and maintaining transmission pipeline

Paint and Coatings Industry News

Main News Page

Bridge Corrosion Closes MN Highway

Wednesday, December 4, 2013

More items for Program/Project Management

Comment | More

A Minnesota interstate has been shut down after corrosion ate away at a bridge support, reportedly to the point that inspectors could see right through it.

A section of southbound Interstate 35 in Duluth, MN, was closed Nov. 18 after bridge inspectors found deteriorated pilings during an inspection. The low-lying section of the bridge sits approximately four feet off of the ground, according to a Minnesota Department of Transportation spokesperson.

"The bridge is being closed as a precautionary measure due to the amount of deterioration that was identified during a recent inspection," Duane Hill, MnDOT District 1 engineer, said in a statement.

The piling was so corroded that MnDOT crews could see right through it, the Grand Forks Herald reported.

The bridge is a 2,100-foot section of highway that is supported by 38 piers with 1,300 steel pilings.

Photos: MnDOT

A MnDOT engineer said that corrosion ate away a "significant amount of steel" on the bridge support.

Originally, the agency expected the closure to last for a few days, but it announced Nov. 21 that the road would remain closed for three to four weeks.

"More substantial repairs are required than we originally thought," Hill said. "The plans we are developing will be safe and efficient for the construction crews to accomplish."

On Aug. 1, 2007, a bridge carrying I-35W over the Mississippi River in Minneapolis, MN, collapsed while 111 vehicles were on it. Thirteen people died and 145 were injured, according to the National Transportation Safety Board's accident report. Minneapolis is about 154 miles south of Duluth on I-35.

'Significant Amount' Corroded

Deterioration was found on the Pier 32 pilings at the bottom of the pier caps where the piling and the cap join. The repair plan being developed includes using a concrete cap extension to transfer the bridge load. Sound steel begins about one foot below where the deterioration was found, and the deteriorated steel will be encapsulated inside the new concrete cap extension, MnDOT explained.

"It ate away most of the steel in those piling supports," Hill told MPRNews. "So a significant amount of steel was gone."

Corrosion was found in all 13 steel pilings that support Pier 32, according to MPRNews.

"The space under that pier was like a mouse hole that you had to have your face right down in the mud to look at. So it was really a difficult thing to ever see... [A worker] just happened to look down there with a flashlight and say, 'hmmm, we should dig this out a little bit more and see what's going on,'" Hill said.

While the cause is still being investigated, MnDOT said that excessive moisture may be a contributing factor. Pier 32 is located in a low-lying section of the bridge in an area with a high water table and poor drainage.

Runoff from I-35 flows through an expansion joint on top of the pier and, combined with water from deck drains on the bridge, runoffs from the bluffs above the freeway, and overflow from Buckingham Creek, the soil beneath the bridge has become saturated.

Interstate 35 bridge corrosion

Repair work on the bridge will take up to a month to complete. The deteriorated steel will be encapsulated in a new concrete cap extension.

MnDOT said it would start the repair work with its maintenance crew before hiring a contractor to complete the work. After assessing repair options, the agency awarded an emergency contract for an accelerated schedule, including multiple shifts per day, seven days per week.

Recent 'Mega Project'

A section of I-35, including the area currently closed, recently underwent a $68 million "mega project," which involved bridge work, including replacing three fracture-critical bridges. The project was completed June 29, 2012, according to MnDOT.

Pat Hudson, MnDOT District 1 Assistant Director of Engineer Operations, said that this bridge was not one of the three replaced.

MnDOT has a bridge preservation project planned for 2015 that will improve drainage and extend the life of this bridge, as well as another bridge. The project plans include reshaping the soil to intercept and drain away the water that has been pooling beneath the bridges.

Wisconsin Pier Corrosion

A similar issue occurred on the Leo Frigo Memorial Bridge in Green Bay, WI, in late September when a 400-foot section of the structure abruptly dropped about two feet overnight.

One of the bridge's piers sank when its steel pilings buckled, "apparently due to corrosion," the Wisconsin Department of Transportation reported. WisDOT said the corrosion was believed to have been caused by a combination of soil composition at the location and the rise and fall of the water table.

However, the Green Bay bridge's piers are situated in water, while the corroded I-35 pier is only driven into the ground.

The Leo Frigo Memorial Bridge carries Interstate 43 over the Fox River south of its mouth into Lake Michigan. An average of 40,000 vehicles use the bridge each day.

Repairing the bridge was ballparked at $50 million, and the Federal Highway Administration mobilized emergency funds after determining the state could not have anticipated the failure.


Tagged categories: Bridge Piles; Bridges; Corrosion; Department of Transportation (DOT); Roads/Highways; Steel

Comment from Richard Hogue, (12/4/2013, 8:16 AM)

Corrosion that extensive doesn't happen overnight. I question why it wasn't found much earlier during routine bridge inspections.

Comment from Kevin Hahn-Keith, (12/5/2013, 7:54 AM)

From the picture and from personal design and inspection experience it does not appear the pile was always visible. I suspect the runoff from the open joint eroded the soil around the base of the pier cap, exposing the pile and also contributing to the corrosion. So a routine inspection would not have caught it. The big questions now are: what is the deterioration of the other piles?, how are those going to be inspected? given this is the second media documented discovery of pile corrosion, what does this mean for the thousands of other bridges supported on invisible (read uninspectable) steel piles? For the state I live in, steel piles are the deep foundation of choice.

Comment from Tom Schwerdt, (12/9/2013, 11:14 AM)

I really hate open joints. Always seem to be designed on top of a bearing for extra corrosion damage.

Comment Join the Conversation:

Sign in to our community to add your comments.

PPG Protective and Marine Coatings Group
Industrial strength performance in ONE can.

Now get the durability and protection of two components in one can: Amercoat® ONE, PSX® ONE and Sigmadur ONE.

Ethox Chemicals LLC
Ethoflex® ER instantly upgrades your epoxy!

The only epoxy additive that improves flexibility, corrosion resistance, toughness, and adhesion, without hurting pot life, cure time, or increasing VOCs.

SAFE Systems, Inc.
Custom blast rooms
by SAFE Systems

Don't waste time and money "making do" with a "standard" design. Let us work with you to design and build the
system that best fits
your requirements.
Call 1-800-634-7278

SABRE Autonomous Solutions
Safety, Productivity, Quality. Robotic Blasting

Learn how this simple to use, field deployed, automatic robot is eliminating hazards in major confined, cluttered and complex surface preparation projects.

Apex Waterjetting Technologies
Waterjetting – Custom Manufacturing and Wholesale

• Waterjet Accessories
• Saphire Nozzles
• UHP Hoses
• Replacement Parts
• Wholesale Direct
• 24 Years of Experience
• Buy and Save!!!

Minerals Research & Recovery

With easy access to mainline railroads and I-40, Minerals Research Inc.’s state-of- the-art plant is situated to serve you better and faster! Steve: 520-297-4626

Mitsubishi Gas Chemical America
Performance Amine 1,3-BAC

A highly reactive cycloaliphatic diamine offering superior performance. Reasonable cost and curing efficacy makes it suitable for all types of epoxy resin applications.

Atlantic Design, Inc.

See our website for features of our best seller, the ADI 3500CFM 4-Pot Blast Vacuum Recycler. A smaller package with all the ADI power you need. 866.Call.ADI

HoldTight Solutions Inc.

Our HoldTight®102 salt remover & flash rust preventer prevents flash
rust by removing surface contaminants. It has no equal; only wannabees.
Contact us for your
nearest distributor.
(800) 319.8802

Thermion Inc
Buy Back Program

We are offering $5,000
credit for your old Model
This drive system is
being discontinued by
the manufacturer.
More information at

Technology Publishing

The Technology Publishing Network

The Journal of Protective Coatings & Linings (JPCL) PaintSquare
Durability + Design Paint BidTracker

EXPLORE:      JPCL   |   PaintSquare News   |   Interact   |   Buying Guides   |   Webinars   |   Resources   |   Classifieds
REGISTER AND SUBSCRIBE:      Free PaintSquare Registration   |   Subscribe to JPCL   |   Subscribe to PaintSquare News
MORE:      About   |   Privacy policy   |   Terms & conditions   |   Site Map   |   Search   |   Contact Us

© Copyright 2000-2015, Technology Publishing / PaintSquare, All rights reserved
2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951; Tel 1-412-431-8300; Fax 1-412-431-5428; E-mail