Virtual inspection based on 3D survey supporting risks detachment analysis in Pietraforte stone built heritage

The paper presents the first results of a multidisciplinary research project launched to support the conservation and restoration of the stone façades of the Pitti Palace in Florence with innovative techniques from the fields of geomatics and diagnostic analysis. Monitoring campaigns are periodically conducted on the façades of the palace to identify stone elements in critical conditions; such surveys primarily require close and careful observation of the façade, for which a crane basket is required. The paper proposes first attempt to compare results obtained through a traditional workflow with those coming from a deeper use of the high-resolution 3D model to conduct a virtual inspection and to map elements of vulnerability on a GIS. On a test area, the analysis of the factors considered relevant to the risk of detachment was carried out on the digital model and compared with what the experts observed on-site by carrying out Non-Destructive diagnostic tests. Traditionally conducted monitoring and diagnostic surveys are assumed to validate the proposed method, which, following a simple data analysis, remotely identifies all blocks detected as vulnerable by the in-situ inspection, potentially drastically reducing fieldwork. It is therefore proposed as a preliminary screening useful to better address further analysis.