(AP) - The National Bridge Inspection Standards sufficiency rating is 38.1 for the bridge, down from the previous rating of 49.1 on a 100-point scale. The drop is linked to corrosion in the bridge's superstructure, the agency said.
The section losses were discovered during an emergency inspection in August that followed the collapse of the I-35W bridge in Minneapolis.
A rating of under 50 means that a bridge needs monitoring, might need to be replaced and is eligible for federal replacement funding. The bridge is the busiest two-lane highway bridge in Minnesota, carrying 32,000 vehicles a day across the Mississippi River between Dakota and Washington counties. "Everybody in Hastings is concerned about that bridge," Hastings Mayor Paul Hicks said. The bridge had already scheduled for $2.2 million in repairs beginning in May.
By 1998, the bridge was already so compromised that MnDOT imposed a 40-ton load limit per vehicle. Last fall, bridge inspectors told MnDOT that the load limit needed to be reevaluated, but in January, MnDOT said no adjustment was needed.
“Everybody in Hastings is concerned about that bridge.”Hastings Mayor Paul Hicks
The private engineering firm that MnDOT hired to perform the August inspection also found broken bearings and 76 cracked welds. That inspection report, uncovered last month by the Star Tribune of Minneapolis, said the 57-year-old bridge needed immediate attention.
MnDOT spokeswoman Lucy Kender said the additional section loss found by inspectors last fall "occurs in areas of the bridge that do not affect its load carrying capacity."
The ratings recalculation means that the Hastings Bridge is now classified under national standards as "structurally deficient," meaning rehabilitation is needed to address the deficiencies.
Katie Sieben, DFL-Newport, said the inspection report shows the bridge "needs to be replaced now." A primary focus of the current legislative session, which began this week, is expected to be transportation spending and taxes.
The Hastings bridge is one of only a few bridges in the Twin Cities region to carry the "structurally deficient" tag. The I-35W bridge in Minneapolis had been classified as structurally deficient, as well as the Lafayette Bridge in St. Paul and the Cayuga Bridge in St. Paul.
Like the I-35W bridge, the Hastings Bridge is fracture-critical, meaning that if one load-carrying part breaks, the whole bridge will fall.
MnDOT said in its latest update that it is reviewing the condition of the bridge's gusset plates and hopes to complete its analysis before this spring's repair project.
The steel plates, which connect truss spans in key parts of a bridge, are a primary focus in the National Transportation Safety Board's investigation into the collapse of the I-35W bridge.
The bridge is not scheduled to be replaced for at least 10 more years.
(Copyright 2008 by The Associated Press. All Rights Reserved.)