The National Transportation Safety Board (NTSB) released more findings about the I-35W bridge collapse, saying federal investigators discovered exactly how individual rivets broke in the crucial gusset plates.
The finished column at Pier 2 after forms were stripped. Photo by Tim Davis, courtesy of FIGG Engineering.
In the fifth update, the report said the bridge’s original design may have been flawed by steel gusset plates that were only a half-inch thick. NTSB also hired engineers from the State University of New York, Stony Brook, who are examining how rivets broke along a fracture line in one of the gusset plates on the west side of the collapsed bridge.
The findings also noted that Progressive Contracting Inc. (PCI), contractors working on resurfacing the bridge, had loaded piles of aggregate near the center line of the bridge and had seven construction vehicles that weighed a total of 312,880 pounds on the bridge. The additional weight may have caused weak gusset plates to fail.
Contractor on the bridge may sue state
PCI may sue the Minnesota Department of Transportation for breach of contract and failing to keep workers safe.
An attorney representing PCI said a public agency is required to provide contractors with a safe place to work. PCI filed a legal notice with the Minnesota Attorney General’s office, but further legal action has to wait until the federal investigation determines what caused the bridge to collapse and independent experts must examine all evidence.
A breach of contract lawsuit would free PCI from Minnesota’s liability limits at $300,000 per person. However, victims would have valid claims against the company and can sue PCI.
Victims’ compensation fund still in debate
The Minnesota Senate unanimously passed a victims’ compensation fund of $26.5 million but set a $400,000 limit on individual claims. The full legislature is asking if the I-35W bridge victims should be treated differently from victims of other disasters.
The state senator who sponsored the bill said the state should not feel compelled to shoulder 100 percent of the financial responsibility to compensate victims, especially when the state has a budget shortfall.
Some victims disagreed, saying that the budget shortfall is not their fault. The lobbyist who represents trial lawyers opposes the cap of $400,000 because many families have losses in excess of that amount.
Half of all concrete to build bridge is poured
Flatiron-Manson crews finished pouring concrete at Abutment 5 and have now placed about 25,000 yards of the 48,700 yards of concrete required for the new bridge. Workers have been careful to protect the concrete from the cold weather and, as the weather gets warmer, will remove the insulation around each column.
Cranes remove forms from Pier 2 southbound on March 15 after the structure cured. Photo by Tim Davis, courtesy of FIGG Engineering.
Construction of the 12 columns for the piers and the abutments required about six weeks from the time concrete was first poured on January 31.
Pre-cast segments continue to be built with 15 segments completed. Each segment is embedded with post-tensioning ducts with high-strength steel tendons running through the ducts. A hydraulic jack will be used to pull on the tendons and compress the concrete segments together.
Traffic and bridge progress coverage increases
Crews are building the support structures on the south approach to Pier 2, forms for the retaining walls between Abutment 5 and the Second Street Bridge, and the Second Street Bridge walls.
As work progresses, streets and bridges in the area will be closed temporarily to accommodate delivery trucks onto the bridge site, relocate utilities, and to ensure safety for motorists, bicyclists and pedestrians. The bike lane on the Tenth Avenue Bridge, west side, is closed on Saturdays during the Superintendent Talks to ensure safety of crowds who view the bridge construction between 11 a.m. to noon.
Television coverage of the bridge construction continues to increase. Jon Chiglo, project manager for the bridge from MnDOT, has been interviewed every week on morning television news.
PR efforts questioned
A newspaper report revealed that Flatiron Constructors, general contractor for the I-35W bridge reconstruction, hired Himle-Horner Inc., a public relations agency with close ties to Gov. Tim Pawlenty, to help restore image to the Minnesota Department of Transportation. The state is paying $550,000 for the PR services that include information kiosks, webcams at the bridge site, TV interviews, and the Superintendent Talks held on Saturdays.
Figg Bridge Engineering made the call to Himle Horner while working on the proposal with Flatiron and included the PR component in its proposal, which MnDOT considered in scoring all submitted proposals that determined selection of the company.
Some Minnesota contractors were irked that the state is spending that amount of money for media attention on the bridge’s predictable progress.