Structural Investigation of the Sherman Minton Bridge Closure

The Sherman Minton Bridge, constructed in the early 1960’s, is a twin double-deck steel tied arch bridge traversing the Ohio River along Interstate I-64 between the states of Indiana and Kentucky. The discovery of previously hidden surface cracks during a gusset retrofit warranted a comprehensive inspection program which revealed numerous cracks and weld indications along the fracture critical tie members, particularly at the vertical butt welded joints. Following the closure of the bridge on September 9, 2011, a structural investigation was initiated to ensure that the bridge would reopen with three principles in mind: safety, schedule and cost. A forensic information model (FIM) of the weld testing inspection program was created to organize available data, illustrate all past and present inspections and to understand any trends. A 3D mathematical model was produced to verify the original design of the superstructure and to evaluate the adequacy of its capacity to support increased loads as a result of the necessary retrofits and repair. This paper will present the process used to evaluate the problem, develop solutions, and construct the retrofit.