Annual Inspection of Twin I-90 Bridges Over Grand River

The scope of work for Ohio Department of Transportation (ODOT) District 12 called for an in-depth inspection of twin truss bridges carrying four lanes of I-90 over the Grand River. Following the initial bridge inspection in the base year, Barr & Prevost conducted routine inspections for the following six years.

Ultrasonic testing of 16 pins was required during two of the inspection years. The inspection of the bridges was visual and by non-destructive testing. Some welded connections required dye penetration tests. In addition to a visual inspection, suspicious areas of substructure concrete were sounded.

Barr & Prevost staff gained access to the lower portion of the bridge by free climbing the bottom truss chord, lateral bracing and diagonals. The upper portions of the bridge were accessed with the use of a 50-foot reach-all inspection vehicle. Piers two and three of the bridge were inspected by free climbing. The remaining piers and abutments were observed from the ground. The inspectors were able to observe the conditions of the deck and parapet walls from the accessible portions of the deck.

Barr & Prevost submitted a bridge inspection report to ODOT each year, which included a narrative with photographs describing where conditions had changed since the previous inspection. A summary of recommendations for repair and maintenance was also included as well as a location map, bridge plan and elevation, bridge typical sections through the truss and girder spans, a completed ODOT BR-86 form and the measurements taken at the expansion joints, girder ends, girder bearings, suspended truss span bearings and bearing blocks, and back walls for the left bridge.