THE CHURCH OF SANTA MARIA DELLE GRAZIE AL CALCINAIO: FROM DIAGNOSTIC STUDIES TO ARCHITECTURAL AND STRUCTURAL REHABILITATION PROJECT.

Michelangelo Micheloni, Anna Livia Ciuffreda , Gabriela Simoni , Federico Salvini

Abstract

 This paper illustrates the results of the cognitive process for the defining structural consolidation interventions, seismic risk reduction and architectural rehabilitation of the church of “Santa Maria delle Grazie al Calcinaio”, Cortona (Arezzo, Italy). The church represents a splendid example of Renaissance architecture in which the architect Francesco di Giorgio Martini rigorously applied the architectural principles of proportion and perspective. The use of local stone (sandstone) is evident inside in the frames that decorate the facades. Today the building has several problems. The most important is the advanced state of decay of the external stone cladding. However, over time the structure has highlighted structural instability that have already required interventions in the past and that have given rise to the need for a static analysis and an evaluation of seismic vulnerability. To this end, a cognitive phase was carried out in accordance to the NTC2018 and the Guidelines for the assessment and reduction of the seismic risk of cultural heritage, which included: historical-critical analysis, digital survey, structural and material diagnostic campaign, HBIM modelling, definition of the structural model and dynamic behaviour. All these studies have made it possible to highlight all the criticalities of the building and to plan interventions aimed at reducing structural vulnerabilities and for securing the stone ashlars and strongly protruding cornices in order to minimize the risk of falling fragments and protect the safety of users.