Back-testing the iconic Polyfytos balanced-cantilever bridge to enhance condition assessment

This paper introduces a comprehensive framework for reliable damage assessment and decision making for bridge intervention planning. By utilising historical data and three-dimensional unmanned aerial vehicle (3D-UAV) photogrammetry, a detailed 3D numerical model is created, incorporating advanced modelling and scenario-based approaches. The methodology is applied to the Polyfytos bridge in Greece, which faces significant vertical deck deflections that disrupt traffic and have an impact on local communities. This approach offers a reliable, cost-effective, and efficient process, allowing stakeholders to make informed decisions with minimal physical interaction with the bridge. The integration of advanced modelling with in situ measurements and expert judgement is emphasised. For the Polyfytos bridge, the framework helps prioritise retrofits and assess the deck’s remaining strength under various loads, providing estimates of its overstrength. This aids in evaluating the bridge’s ability to handle additional vertical loads through pushdown analysis. Overall, the framework is valuable for rapid infrastructure assessment, identifying damage patterns, severity and the urgency of interventions related to structural strength.