Phone call put brakes on bridge repair

Plans to reinforce the bridge were well underway when the project came to a screeching halt in January amid concerns about safety and cost.

The men and women whose job was to ensure the safety of Bridge 9340 were meeting once again. Just after noon on Dec. 6, they filed into a conference room in Roseville to divvy up the final prep work for a dangerous steel reinforcement project high above the Mississippi River.

A senior engineer was going to pull property records in order to contact landowners beneath the bridge. Detours were coming for West River Road. The Coast Guard was about to get heaps of paperwork on what tasks would be done from the river channel. Truck drivers would soon learn of pending weight restrictions.

It appeared that the most studied bridge in Minnesota, the focus of worrisome inspection reports for a decade, was finally going to have its most glaring weaknesses fixed.

But five weeks later, all those preparations stopped. In a single conference call on Jan. 17, the same consultants who said reinforcement plates were needed to strengthen the bridge cautioned MnDOT that drilling for the retrofit could weaken it.

"That was the turning point. That's where we turned the ship 180 degrees," said state bridge engineer Dan Dorgan.

Internal MnDOT documents reviewed by the Star Tribune reveal that last year bridge officials talked openly about the possibility of the bridge collapsing -- and worried that it might have to be condemned.

The documents provide the first look inside MnDOT's decision-making process as engineers weighed benefits and risks, wrestling with options to prevent what they believed was a remote but real possibility of the eight-lane freeway bridge failing.

Their concerns were not generalized, documents show. The San Francisco-based consultant, URS Inc., identified 52 crucial steel box beams deemed most susceptible to cracking. URS also had a specific recommendation that 24 of the 52 members be reinforced while the remainder would be kept on a special watch. Video of the Aug. 1 collapse being examined by the National Transportation Safety Board shows the bridge first falling on the south end over its shoreline pier -- a section of the superstructure where eight suspect beams were specifically tagged for reinforcing.

'Investment strategy'

Dorgan and senior engineer Gary Peterson denied in interviews that money was a factor in deciding what to do with the Interstate 35W bridge, which was not due for replacement until 2022. They provided a written timeline showing that MnDOT supervisors on Nov. 1, 2006, funded the reinforcing project for $1.5 million, with work to begin in January 2008.

But at least three internal documents suggest that money was a consideration.

On Jan. 18, one day after MnDOT's Bridge Office opted to inspect rather than reinforce the bridge, Peterson apologized to an engineer in the department's Metro Design section that work put into the reinforcing project was for naught.

"We regret the additional work this has caused you and others in the district," Peterson wrote in an e-mail, "but I'm sure you agree that based on this new information it [is] appropriate that we postpone the project until we can determine if another option may [be] as safe and a more cost effective approach."

Earlier, when MnDOT and its consultants were zeroing in on reinforcing the bridge, an internal MnDOT "investment strategy" meeting was held on July 24, 2006, in which officials debated various approaches.

According to meeting minutes, officials said that immediately installing steel reinforcements would greatly reduce the risk of a crack forming "between now and 2022." That way, the agency could pick the ideal time and circumstances for carrying out the work.

The "risk" of that approach was described this way: "Must pay approximately 2 million dollars to get the job done."

A logistics and financial issue also was discussed. MnDOT officials said that if the bridge was simply inspected, the benefit would be: "Don't have to pay for steel, stockpile steel, or install steel."

The downside of such a decision, MnDOT officials acknowledged in the meeting, was that "If a crack is found it will take 4 months to order steel and reinforce the bridge, and the bridge will be closed to traffic for this duration. But there is a further risk that the damage is beyond fixing, and the bridge will have to be condemned. This means 35W will be closed for a minimum 5 years until the new bridge is finished."

  • related content

  • Graphic: Safeguards were in the works for critical box beams

    Saturday August 18, 2007

    All about box beam structure and potential hazards. Users can also see different URS failure...

  • Graphic: Adding an extra lane on I-94

    Friday August 17, 2007

    Weather permitting, the Minnesota Department of Transportation will close I-94 in both directions between Hwy....

  • Weekend traffic flow good despite work on I-94 section

    Saturday August 18, 2007

    There were slowdowns and a few minor bottlenecks, but overall there were no reports of serious congestion.

  • Road work will continue through weekend, despite rain threat

    Saturday August 18, 2007

    Crews will need some dry time to add two lanes to I-94, which will have 3 miles between I-35W and Hwy. 280 closed to traffic.

  • In about-face, Pawlenty backs an LRT-ready bridge

    Friday August 17, 2007

    It would take an estimated extra $20 million to $30 million, but that might be a price worth paying, the governor said.

  • Honoring those who kept their cool

    Friday August 17, 2007

    Chalk up another honor for Jeremy Hernandez, a reluctant hero of the I-35W bridge collapse.

  • City seeks unity in designing bridge

    Thursday August 16, 2007

    Minneapolis City Council moving to send message of cooperation with state. It plans to adopt principles today.

  • As state money diminished, so did goals for bridge safety

    Thursday August 16, 2007

    MnDOT officials said they revised goals to adjust to what other states were doing.

  • City Council nears 'statement of principles' on new bridge

    Thursday August 16, 2007

    Minneapolis City Council moving to send message of unity, cooperation. Council plans to adopt principles Friday.

    • get related content delivered to your inbox

    • manage my email subscriptions


    Connect with twitterConnect with facebookConnect with Google+Connect with PinterestConnect with PinterestConnect with RssfeedConnect with email newsletters






    question of the day

    Poll: Do you agree with the NFL decision to deny Adrian Peterson's appeal?

    Weekly Question


    inside the StarTribune