A Multidisciplinary Approach to the Restoration of the Pyli Arch Bridge: Integrating Seismic, Geotechnical, and Hydraulic Analyses
A Multidisciplinary Approach to the Restoration of the Pyli Arch Bridge: Integrating Seismic, Geotechnical, and Hydraulic Analyses
Abstract
This paper presents a comprehensive assessment and restoration strategy for the historic stone arch bridge of Pyli (Agios Vissarion Bridge), a protected monument likely constructed in the early 16th century. Following the extreme flood event caused by Storm Daniel in September 2023, the structural safety of the bridge was re-evaluated due to emerging concerns regarding foundation scour and seismic vulnerability.
The investigation integrated architectural documentation, material pathology, and finite element modeling with a detailed evaluation of the geotechnical and hydraulic conditions. A key finding was the asymmetric foundation configuration: the north abutment is seated on competent limestone, whereas the south abutment rests on thick, loose riverbed deposits that are highly susceptible to erosion and dynamic loading. Progressive scour at the south abutment was identified as a primary failure risk, consistent with damage patterns documented in other historic masonry bridges across Greece.
Advanced analyses included staged-construction 3D finite element modeling, 2D soilstructure interaction simulations, and seismic performance evaluation in accordance with EN 1998-1 (Eurocode 8) and KADET for seismic events with return periods of 475 and 914 years. The bridge exhibited satisfactory performance under moderate seismic loading; however, localized instabilities associated with scour-induced foundation degradation were confirmed.
The proposed restoration measures comprise deep ground improvement (jet grouting), protective soil encasement, and perimeter micropiling around the south abutment. These interventions are designed to mitigate flood-induced scour and enhance seismic resilience while preserving the historical and architectural integrity of the structure.
Overall, the proposed multidisciplinary methodology offers a balanced and replicable framework for the preservation of masonry heritage structures exposed to multi-hazard environments.
Keywords: Historic stone bridge, Seismic assessment, Geotechnical conditions, Flood induced foundation scour, Masonry structures, Restoration strategy
Dimitrios Egglezos; Christos Giannelos
4th International Symposium on the Preservation of Monuments and Historic Sites
Seismic Behaviour of Heritage Monuments: Observation, Modelling and Mitigation
https://doi.org/10.53243/tc301-2026-59