The Iowa Department of Transportation's bridge inspection team has concluded its examination of the U.S. 34 bridge over the Mississippi River at Burlington and determined it can be reopened to traffic.
The inspection included an “arms-length” under-bridge visual inspection of the pier that was struck, two adjacent piers and all related key structural elements, according to a statement by the Iowa DOT. In addition, an underwater probe was used to check the pier for any damage to the protective metal plate and concrete.
The inspection concluded that there was no structural damage to the bridge, also known as the Great River Bridge. Only minor blemishes were found from what apparently was a glancing blow. No damage to the deck or support cables was observed.
The pier on the eastern end of the bridge was struck by two runaway barges full of coal in the early morning of May 1. The barges were among five owned by Matteson Marine of Burlington. The five barges broke free of their moorings on the flood-swollen Mississippi, the Burlington Hawk Eye reported, and floated downstream into the bridge.
A second bridge, which carries rail traffic including Amtrak passenger service and is located downstream from the U.S. 34 bridge, also was struck by a third barge. That bridge remains closed. The barge remains wedged against the railroad bridge structure. The rail bridge is owned by the Burlington Northern Santa Fe (BNSF) Corp., headquartered in Fort Worth, Texas.
The U.S. 34 bridge is the first cable-stayed bridge ever built in Iowa. It carries four lanes of traffic between Burlington, Iowa, and Gulfport, Ill. The three-span bridge has a total length of 1,245 ft and was completed and opened on July 14, 1995. Under normal conditions, it carries about 8,600 vehicles a day.
The Iowa DOT said the pier that was struck had a very significant foundation that is supported on 144, 150-ton H-pilings embedded into rock below the stream bed.