Bridge Load Programmatic (2014)

Project Overview

Ribway was selected by the Fairfield County Engineer’s Office to perform structural inspections and load ratings for multiple bridges and culverts throughout the county. This project aimed to assess the structural conditions of these infrastructure assets and determine their safe load-carrying capacities.

Scope of Work

1. Field Inspections
   • Evaluated the superstructures of bridges, including beams and decks.
   • Assessed culverts, focusing on the top slab and walls.
   • Measured section loss on structural members to ensure accurate condition assessments.
   • Captured digital photographs and field notes for documentation.
2. Load Rating Analysis
   • Load ratings calculated per Load Resistance Factor Rating (LRFR) methodology.
   • Level I Bridge types analyzed:
     • Timber decks on non-composite steel girders.
     • Steel plate deck on non-composite steel beams.
     • Prestressed adjacent box beams.
     • Reinforced concrete, cast-in-place box culverts.
3. AASHTO Bridge Rating (BrR) 6.5 Software & Manual Calculations
   • Modeled and analyzed structures using AASHTO BrR 6.5 (formerly Virtis).
   • Manual calculations were conducted for culverts using steel mesh reinforcement, as BrR 6.5 did not support direct modeling of these structures.
   • Verified results using Fairfield County’s internal load rating spreadsheet.
4. Deliverables
   • Load Rating Summary recorded using Form BR-100.
   • Load Rating Reports generated for each structure.

Project Completion

• Timeline: Completed within two months.
• Outcome: Provided Fairfield County with critical structural assessments, ensuring informed decision-making for bridge and culvert maintenance and safety.