Prediction of the flexural behavior of corroded prestressed concrete girders: a probabilistic multi-level approach

Abstract

This paper introduces a probabilistic multi-level framework for predicting the flexural behavior of corroded prestressed concrete (PSC) girders. The proposed framework employs a hierarchical modeling strategy that progresses from the wire to the girder level and integrates detailed finite element (FE) analysis, surrogate modeling, and Monte Carlo simulations. This computationally efficient framework addresses the challenge of accurately predicting flexural behavior by systematically incorporating the effects of the geometric complexity of the corroded strands and other inherent modeling uncertainties into its probabilistic predictions. The surrogate model constructed from the FE results enables efficient predictions by accounting for material and geometric uncertainties across multiple structural levels. Experimental validation was performed using ten PSC girder specimens, comprising both single- and multi-strand configurations, subjected to controlled corrosion and flexural loading tests. The predicted load-displacement responses, including the 50 %, 95 %, and 99 % prediction ranges, exhibited good agreement with the experimental results, successfully capturing key indicators of structural performance, such as loads and deflections at yield and ultimate. In addition, a global sensitivity analysis identified the dominant sources of uncertainty influencing the variability in the probabilistic predictions. These findings confirm the ability of the proposed framework to accurately model corrosion-induced degradation and reliably quantify the associated uncertainties.