Resilience Analysis of Different Retrofitting Solutions for a Prestressed Concrete Viaduct

Abstract

This article introduces a resilience analysis conducted on Greece’s prestressed Polyfytos viaduct. As the nation’s second longest bridge, spanning 1,372 meters, it was conceptualized by Prof Riccardo Morandi and built between 1972 and 1975, marking it as an iconic structure at 48 years old. Notably, the bridge has strong interdependencies with key power plants, dams and solar pars in the region. Evaluating both risk and resilience, the study employed visual inspections and digital data collection methods. These methods involved a digital twin, offering current asset geometry and a dynamic model for advanced simulations; satellite imagery for ongoing updates on the structure’s deformations and geometry; and advanced numerical modeling aimed at interpreting current deflections via back analysis. The bridge shows signs of degradation commonly found in reinforced concrete (RC) and prestressed RC (PRC) bridges, specifically concerning corroded tendons and concrete bonding. Prior research focused on evaluating various retrofitting approaches and their lifecycle impacts, whereas this study integrates the resilience assessment of such retrofit solutions. This contribution represents a new step in the direction of a holistic approach to identifying the appropriate retrofit of an existing viaduct aiming to inform decision-making about the benefits of different restoration investments.