AIE has load rated 916 bridges statewide for Montana Department of Transportation. These bridges are being load rated using AASHTOWare BrR per LRFR methodology in accordance with AASHTO LRFR and Montana guidelines. When BrR is unable to rate a bridge due to complexity or geometric considerations, more refined analysis is being performed using manual calculations, MDX, or STAAD.Pro. Limit states rated and reported include Strength and Service. Both standard line girder and more refined 3D FEM analyses are included in this project. Field measurements and inventory documentation is required for bridges without plans and data collected is submitted as part of the overall load rating package. Bridge types include deck trusses, steel box and I-girders, prestressed beam and slab bridges, reinforced concrete t-beam and slab bridges, and corrugated steel pipe culverts.

Bridge components load rated include:

• Superstructures (stringers, floorbeams, girders, truss chords)
• Pier Caps (steel)
• Gusset Plates
• Splice connections
• Culverts
• Other components considered critical based on their condition