Reliability-based vulnerability assessment of steel truss bridge components

Bridges are among the most vulnerable and expensive assets of transportation networks. The failure of a bridge component can lead to catastrophic consequences for the entire structure. Therefore, vulnerability assessments have gained prominence to ensure their structural safety. However, as bridges age, performing a reliable assessment becomes increasingly challenging. This paper proposed a framework for the component-based vulnerability assessment of steel truss bridges. An index (SoD) that quantifies the State of Demand of each structural element is proposed. The level of vulnerability of all bridge elements is evaluated through a FEM-based approach that considers the uncertainty of the variables affecting the structural behaviour. The proposed framework has been tested in a real steel truss bridge located in Galicia, Spain. The framework finally integrates finite element modelling, uncertainty quantification and propagation, and probabilistic tools into a systematic approach for evaluating the component-level vulnerability of steel truss bridges. The outputs can be used to optimise inspection routines, reduce costs, and support the decision of authorities regarding bridge safety, monitoring, and maintenance. This work breaks new ground in the practical application of new knowledge, as the methodology could be further automated, simplifying engineering efforts and supporting bridge management entities to improve the bridge’s structural safety.