Seismic Vulnerability Assessment of a Medieval Urban Cluster Identified as a Complex Historical Palace: Palagio di Parte Guelfa in Florence

This paper presents the results of the application of a holistic procedure for a seismic vulnerability analysis of complex masonry aggregates which are ascribable as cultural heritage buildings. The methodological framework allowed us to properly identify the structural units comprising a historical palace through a hierarchical approach combining integrated geometrical and structural surveys with non-destructive (ND) and minor destructive (MD) techniques. The investigations were conducted on a significant palace located in the historical center of Florence, the Palagio di Parte Guelfa. The building covers an entire urban block, as it is constituted by many structural units developed over the centuries since the Roman period. The palace incorporates pre-existing structures, such as the Church of Santa Maria Sopra Porta and medieval terraced houses. Over the decades, different restorations and renovations have been carried out, including by Filippo Brunelleschi in the XV century and by Vasari in the XVI. Nowadays, the building constitutes an urban cluster. Our seismic vulnerability analysis took advantage of a specific knowledge path which was suitable for the identification of the different structural units of the palace. To this end, the historical evolution of the construction was traced through bibliographic research and ND surveys. We finally assessed the seismic performance of the different units according to different approaches, i.e., a rapid assessment based on simplified computations at the global scale, and a kinematic analysis for local phenomena.