Fragility analysis of prestressed concrete girder bridges to traffic loads considering tendon corrosion

The paper is focused on the probabilistic structural assessment of existing prestressed concrete girder bridges accounting for traffic loads. Particularly, this study concerns the fragility of the class of prestressed concrete girder bridges characterized by post-tensioned tendons built in the 1960-1970 period. The structural safety of such bridge class can be affected by construction errors involving voids in the ducts and degradation conditions in terms of tendon corrosion which can be hardly detected during on-site visual inspections. The study applies a fragility analysis algorithm to investigate the probabilistic response under traffic loads considering the uncertainty related to material and geometric variables for different scenarios of tendon corrosion. The algorithm is applied for two typical case-study configurations of simply supported superstructures. The achieved results can be considered as a basis for future typological studies which can be used as a decision support for transport managers to define risk-informed refined assessment plans.