INVESTIGATION AND ANALYSIS OF THE FRACTURED GIRDER IN BRIDGE NO. 9800, T.H. 56 OVER MISSISSIPPI RIVER IN ST. PAUL, MINNESOTA

A detailed study of the fractured girder in Bridge 9800 (LaFayette Bridge) over the Mississippi River was made using material from the cracked girder. The results of the study indicate the fracture of a main girder of the LaFayette Street Bridge was due to the formation of a fatigue crack in the lateral bracing gusset to transverse stiffener weld.