Project Owner

Illinois Department of Transportation (IDOT)


WSP | Parsons Brinckerhoff

Services Provided

NBIS Bridge Inspection and Bridge Rating


Statewide Illinois

Year of Inspections


Major River Bridge Inspection and Rating – IDOT BBS

HBM Engineering Group collaborated with WSP USA (Parsons Brinckerhoff) to conduct a comprehensive inspection of major river bridges. The initiative aimed to assess the structural integrity, identify potential issues, and ensure the safety and reliability of these critical transportation links. The primary goal of the major river bridge inspection was to ensure the structural soundness of key transportation assets. By employing a multi-faceted approach, including both conventional and advanced inspection methodologies, the project aimed to provide a comprehensive understanding of each bridge’s condition.

Inspected Bridges:

  1. I-64 over Wabash River (S.N. 097-0003 & 097-0004)
  2. IL 136 over Illinois River (S.N. 063-0002)
  3. Keokuk Bridge US 136 over Mississippi River (S.N. 034-0062)
  4. I-74 over Illinois River (S.N. 090-0001)
  5. IL 178 over Illinois River (S.N. 050-0088)
  6. Centennial Bridge US 67 over Mississippi River

HBM’s Scope:

  • NBIS Bridge Inspections
  • Fracture-Critical Inspections
  • Underwater Inspections
  • NDT Testing

Inspection Methodologies:

  1. NBIS (National Bridge Inspection Standards):

    • Adherence to national standards to evaluate structural elements and overall bridge conditions.
  2. Fracture Critical and Element Level Inspection:

    • In-depth scrutiny of critical components and individual elements for vulnerabilities.
  3. Underwater Investigation:

    • Utilization of underwater inspection techniques to assess submerged components.
  4. NDT Testing on Pin and Links:

    • Non-Destructive Testing (NDT) to analyze the condition of pins and links in the bridge structure.
  5. Ultrasonic Thickness Gage Measurement:

    • Precise measurement of steel member thickness for structural health assessment.
  6. Dye Penetrant Testing:

    • Identification of surface-breaking defects in steel members through dye penetrant testing.
  7. Underwater Sonar Inspection:

    • Implementation of sonar technology to investigate substructure scour conditions.

HBM Engineering Group, in collaboration with project partners, demonstrated a commitment to upholding safety standards and ensuring the reliability of major river bridges critical to regional transportation networks.