Thread: Feds: Design Flaw in Bridge Collapse

Feds: Design Flaw in Bridge Collapse

Tuesday, January 15, 2008 1:50 PM

WASHINGTON -- Undersized gusset plates in the Interstate 35-W bridge in Minneapolis were "the critical factor" in the bridge collapse last year that killed 13 people and injured 100, the National Transportation Safety Board said Tuesday.


Chairman Mark Rosenker said the plates, which connected steel beams, were roughly half the thickness they should have been because of a design error. Investigators found 16 fractured gusset plates from the bridge's center span, he said.

"It is the undersizing of the design which we believe is the critical factor here. It is the critical factor that began the process of this collapse. That's what failed," Rosenker said.

The Minneapolis bridge was a steel-deck truss bridge that opened in Rosenker said it wasn't clear how the design flaw made it into the bridge because investigators couldn't find the design calculations.

Once they made it into the completed bridge, he said, there was little chance they would be noticed by inspectors.

There are about 465 other steel-deck truss bridges around the country. Rosenker said the safety board had no evidence that the deficiencies in the Minneapolis bridge design "are widespread or go beyond this bridge."

But he cautioned that states and contractors should look at the original design calculations for such bridges before they undertake "future operational changes."

The Minneapolis bridge was deemed "structurally deficient" by the federal government as far back as 1990, and the state's maintenance of the structure has been questioned. But Rosenker said the NTSB investigation has found no evidence that cracking, corrosion or other wear "played any role in the collapse of the bridge."

Investigators also found no flaws in the steel and concrete material used in the bridge.

In his update Tuesday, Rosenker also noted structural weight had been added to the bridge in two major renovations, as well as construction materials that were on the bridge the day it collapsed as part of a resurfacing project.

The findings are consistent with what the NTSB said about a week after the Aug. 1 collapse, in which the bridge plunged into the Mississippi River. At the time, the NTSB said it had found issues with the collapsed bridge's gusset plates, but expected a full investigation to take more than a year.

Transportation Secretary Mary Peters was expected to issue an advisory urging states to check the gusset plates when modifications are made to a bridge—such as changes to the weight of the bridge or adding a guardrail, said a federal official with knowledge of the plans. The official spoke on condition of anonymity because Peters had not yet made the announcement.

Currently, such calculations are done for the entire bridge, but not down to the gusset plates, the official said.

Last August, Peters advised states to consider the additional stress placed on bridges during construction projects. An 18-person crew was working on the bridge when it collapsed.

Nearly three months later, she told a gathering in Washington of a "working theory" of a poorly designed gusset plate and a heavy load of construction materials.

Meanwhile, state lawmakers announced plans last month to spend up to $500,000 to hire legal counsel to aid in a legislative inquiry into the collapse.

Late last year, President Bush signed a massive spending bill which included $195 million to help replace the bridge. That came on top of the $178.5 million the federal government has already given Minnesota for the project.

The bridge was originally designed by Sverdrup & Parcel, a company acquired in 1999 by Jacobs Engineering Group Inc. of Pasadena, Calif. A message left by The Associated Press with Jacobs wasn't immediately returned.

http://www.newsmax.com/us/Feds:_Design_ ... 64524.html

OK... I gotta comment and throw in my 2 cents. As an Engineer myself this appears to be a cover up and has been from the very beginning.

Not in the conspiracy sence ... but in the sence that we have over 80,000 + bringes in this country and just about 80% are functionally deficiant

As money gets pulled from the federal DOT and diverted to support this NAFTA highway I project you are going to see more deaths in the future or at the very minimum more catistrophic falures to one degre or another.

The term bambozzelled comes to mind when we start talking about Federal funding (Your Tax Dollars) and how they misappropriate throughout this government with little to no oversight

Shut down the NAFTA corridor and bring these politicians to justice that are robbing you blind while you graciously foot the bill

PREMEDITATED MERGER
Officials warned NAFTA trucks threatened bridge
Increasing traffic from international trade placed undue stress on Minneapolis span

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Posted: August 7, 2007
1:00 a.m. Eastern


By Jerome R. Corsi
© 2007 WorldNetDaily.com



Interstate 35W bridge in Minneapolis after collapse Wednesday (Courtesy St. Paul Pioneer Press)
Public officials in Minnesota had been warned that increasing truck traffic from international trade was placing an undue stress on the state's transportation infrastructure, including specific warnings concerning the now-collapsed bridge over the Mississippi on Interstate 35W in Minneapolis.
As WND reported, a Federal Highway Administration study begun in 1998 warned increased NAFTA truck traffic would endanger Minnesota bridges along I-35.

A separate study by the Minnesota Department of Transportation, or MNDOT, published in May 2005 – a "Minnesota Statewide Freight Plan" – identified the need to improve bridge and pavement deficiencies affecting trucks.

The MNDOT website also archives a June 2006 "Fractural Critical Bridge Study" that recommended replacing Bridge #9340 ("Squirt Bridge"), the now collapsed span on I-35W in Minneapolis.

(Story continues below)


Before collapsing, the bridge was not under any restrictions, despite multiple reports of deficiencies. Overweight trucks were permitted to carry loads of up to 136,000 pounds on the interstate.

Estimates are that the collapsed I-35W bridge carried 144,000 vehicles per day, including 4,760 commercial vehicles.

Internal documents from MNDOT and the Dallas-based trade organization NASCO – North America's Supercorridor Coalition – show the Minnesota agency joined NASCO to help deal with the strain NAFTA and other world trade freight loads were placing on the state's I-35 infrastructure, including support to repair the Minneapolis bridge.

In a Feb. 15, 2006, letter, Abigail McKenzie, director of the MNDOT Office of Investment Management, wrote to Melvin identifying a list of approximately 100 MNDOT requests for NASCO to assist with finding funding for the years 2007-14, including a request for $3 million to "replace overlay, joints, repair anti-icing, etc." on the I-35W bridge.

A July 19, 2006, memo written by Brad Larsen, MNDOT federal relations manager, to the MNDOT division directors stressed several benefits of joining NASCO, including the possibility of help to lobby for additional discretionary federal highway funds.

Larson's letter also pointed out NASCO state membership typically cost $50,000 a year, but NASCO had allowed Oklahoma to join for $25,000, and Larson believed he could get a special exemption allowing Minnesota to join NASCO for only $15,000 a year.

To further induce MNDOT to join, Larsen noted NASCO's executive director, Tiffany Melvin, had offered MNDOT two positions on the NASCO board of directors.

A Dec. 16, 2006 letter from Melvin to MNDOT acknowledged receiving MNDOT $15,000 fee to become a NASCO member.

The file indicates MNDOT internal support to join NASCO was far from universal.

In a March 7, 2006, memo, Robert Gale, an MNDOT planner, wrote, "I do not see that Mn/DOT has much, if anything, to gain by giving these people $50,000 or $25,000 or anything for that matter." He continued, "I would say we should save the state's money for more worthwhile endeavors than this group has to offer."

There is no record in the file that NASCO was ever able to assist MNDOT with the $3 million request to repair the I-35W bridge.

International trade dramatically increases traffic

Truck traffic carries the vast majority of international trade. According to the FHWA, in 2002, trucks carried 797 million tons of international shipments, valued at approximately $1.2 trillion. By 2035, trucks are projected to carry 2.1 billion tons of international freight, valued at approximately $6.2 trillion.

By contrast, rail, the second largest carrier of international freight, is expected to grow from 200 million tons in 2002 to 397 million tons in 2025. The value of international shipments carried by rail is projected to grow from $114 billion in 2002 to $275 billion in 2035.

The FHWA estimates Minnesota is experiencing what is expected to be an 84.3 percent increase in truck tonnage on the state's highways from 1998 to 2020.

FHWA reports leave no doubt truck traffic is particularly damaging to U.S. bridge and highway infrastructure and that international trade is projected to increase traffic dramatically on U.S. highways.

The FHWA estimates trucks are responsible for 40 percent of FHWA program costs but account for less than 10 percent of total vehicle miles traveled.

A frequently cited road test conducted by the American Association of State Highway Officials established that it takes 9,600 cars to cause the road damage caused by one fully-loaded, 80,000-pound truck.

Even though subsequent research has refined the estimate, the overall disproportionate road damage by heavily loaded trucks, including damage to bridges, is well established.

With growing truck traffic carrying more international trade, the FHWA concludes, "Clearly, more traffic is moving over essentially the same infrastructure."

Between 1980 and 2002, the FHWA reports truck travel grew by more than 90 percent, while lane-miles of public roads increased by only 5 percent.

The FHWA openly admits, "The creation of NAFTA has fostered north-south traffic, placing more demands on the domestic transportation system."

As WND has reported, the importance of international trade to I-35 has resulted in the interstate being designated as the "NAFTA Superhighway," even by prominent trade associations such as NASCO.

http://www.wnd.com/news/article.asp?ARTICLE_ID=57029

The cost of a new bridge and damages resulting from the collapse of this one should come out of Bush's Mexican pilot truck project fund he continues to operate despite congress' legislation to the contrary.


We cannot afford to fund NAFTA and the roads and bridges it requires.