State transportation officials are avoiding weeks or even months of wait time in inspecting underwater bridge components by using the latest in sonar imaging technology. The method’s potential will become the focus of a federal study next year.
This spring’s record floods posed high risks for the 80-year-old Sorlie Bridge, which connects Grand Forks, N.D., and East Grand Forks, Minn. Flowing 30 ft higher than normal, the fast-moving Red River of the North engulfed the 605-ft-long, two-span truss structure’s timber pilings and lapped at its lower beams, conditions that can lead to severe scouring.