Application of Performance Curves as a Method of Condition Assessment of Fatigue-Critical Steel Bridges: The Ramón Nonato Pérez Steel Truss Bridge in Colombia

This paper investigates the fatigue performance of the Ramón Nonato Pérez steel truss bridge in Colombia using a numerical simulation approach that incorporates cumulative traffic-induced damage. After nearly 40 years in service, and with no prior fatigue assessment available, a recent inspection revealed significant corrosion in critical elements, highlighting the urgent need for evaluation. A finite element model, developed from existing drawings, was subjected to American Association of State Highway and Transportation Officials (AASHTO) fatigue truck loadings to simulate stress histories. The analysis incorporated key parameters such as structural redundancy, corrosion effects, bridge age, fatigue-prone connection geometry, and traffic growth. Special emphasis was placed on quantifying corrosion's impact on remaining fatigue life. Simulation results are presented as fatigue failure probability curves for individual elements and the entire structure, offering insights into failure progression. These curves identify the most vulnerable components, aiding in prioritization for repair, rehabilitation, or replacement. Beyond assessing the current condition, the methodology supports future retrofitting plans and can inform condition assessment and management of similar aging, fatigue-critical steel bridges lacking prior vulnerability analyses.