Client

Indiana Department of Transportation (INDOT) Vincennes District

Background

Built in 1956, the one-mile-long Wabash Memorial Bridge is a two-lane structure crossing the Wabash River between Indiana and Illinois. Its main structure is a three-span, tied arch through-truss bridge flanked by six plate girder approach spans on each side. The remaining structure is a multiple-span, conventional steel bridge over a floodplain. This structure has thirty-six spans of wide flange girder superstructure set on hammerhead piers, which constitute over one-half the bridge length.

Solution

WJE's field investigation assessed the existing systems and included a fracture-critical inspection of the upper steel truss members, floor beams, and stringers; and a condition survey of the concrete, deck, steel girders, diaphragms, bearings, and piers. Select concrete cores were removed for laboratory study and petrographic examination. WJE performed a delamination survey of the entire bridge deck and evaluated the overcoat paint system. Gravity, fatigue, scout, and seismic structural analyses were conducted on various elements, and load tests were used to assess actual stress ranges in Category C and E fatigue details. Onsite inspection and laboratory analysis identified causes of distress and led to effective repair recommendation strategies. WJE presented the flowing recommendations to extend the bridge's service life:

Address existing concrete deterioration on piers

Plan for ongoing monitoring of fit-up tack welds and other fracture critical details

Options for seismic retrofit and deck replacement

Strategies for coating maintenance and repainting

Development of Inspection and Maintenance Manual for INDOT