A simplified framework for reliability assessment of prestressed concrete bridge girders under travelling loads in dynamic regime

Abstract

Assessing the reliability of prestressed bridge girders is paramount to keeping transportation infrastructure functional. Classical structural reliability assessment requires computing the demand and capacity of the components of interest. In this study, a simplified approach for travelling loads on bridges in dynamic regime is used to calculate the demand in the girders in terms of bending moment and shear force. The structural demand is then compared with the corresponding capacity values computed by accounting for the ageing of the construction materials at different times over the life cycle of a bridge. A numerical fiber-based modelling approach is adopted to compute the ultimate bending capacity of the prestressed girder; a code-based approach is adopted for computing the shear capacity. The main epistemic uncertainties are propagated with a simple Monte Carlo simulation. An existing Italian reinforced concrete viaduct is presented as a case study. Results show that the proposed simplified approach is acceptable for assessing structural reliability along the asset life cycle.