CTDOT Load Rating

Statewide, CT

AI has been providing bridge inspection and load rating services to CTDOT since 2002. The load rating project has involved 117 bridges to date. The bridges include Class I (simple), Class II (moderately complex) and Class III (complex) bridges. The bridges in the load rating assignment have included steel multi girders, two main girders with floor beam/stringer system, trusses including deck truss system bridges, prestressed concrete multi girder bridges (adjacent deck units, box girder bridges, I girders), multi span concrete arches and curved steel box girders. A variety of software is being used to analyze the different type of bridges. STAAD.Pro, BrR and PS3 are being used to model and analyze a majority of the bridges in the assignment. MDX software has been utilized to analyze and rate the steel curved box girder bridges. Some support programs like Mathcad and Excel spread sheets are being used in the assignment as well. During the course of the assignment, we discovered that some of the bridges did not have plans. Those bridges required special attention and field inspection to determine the geometric data of the bridge and sizes of the concrete members. Also specialty work was assigned to a testing lab company to determine the size and location of the reinforcement in the concrete members. The steel bridges will need an in-depth inspection with emphasis on needed information for load rating and identifying and documenting the sizes of the structural members and locating and measuring any section loss. The load rating analysis work is according to AASHTO specification and Connecticut load rating guidelines.


  • Client: CTDOT
  • Duration: 2002 - Present
  • Project Scope:
    • Load rating
    • NBIS inspection
    • NBIS guidelines/BrM
    • Fracture critical & special inspection
    • Structure safety flag
    • MPT