14. Lafayette Street Bridge

Donated by: Minnesota Department of Transportation (MnDOT)& Lunda Construction
Original Location: St. Paul, Minnesota
Year Built: 1968
Year of Fracture: 1975, girder fracture
Replaced: 2014, due to old age and condition
Donated to SBRITE: June 2015

Structure Type: Plate Girder Bridge
Total Bridge Length: 3366 ft
Longest Span Length: 362 ft
Deck Width: 61.4 ft

The Lafayette Bridge was opened to traffic in 1968. It carried U.S. Route 52 across the Mississippi River, the railroad yards north of the river, and the industrial areas south of the river near St. Paul, Minnesota. It was a fracture critical structure that could collapse due to the failure of a supporting element.

In 1975, the east girder on the southbound bridge fractured. This caused a 7-inch dip in the roadway. The fractured girder was jacked back into place and bolted together with splice plates. The cause of the fracture was a fatigue crack that started in a weld between a lateral gusset plate and a vertical web stiffener.  It is an excellent specimen illustrating the repairability of steel girders.  Other components donated include a “ship-lap” finger/tooth dam expansion joint that has significant corrosion.