Diagnostic surveys at very important historical buildings: The Cathedral of SS Annunziata in Castro (Lecce, Southern Italy).

Within the project restoration regarding the static improvement of the northern façade of the S.S. Annunziata Cathedral in Castro (Lecce), integrated geological and geophysical investigations were undertaken. The aims of the survey were to define the model of the local geological stratigraphy and to evaluate the geotechnical characteristics of the ground hosting the foundation of Cathedral. Geophysical survey was performed used Ground Penetrating Radar integrated with seismic refraction tomography. Moreover both a direct investigation using continuous core boring and a hand excavation were performed in correspondence of the building foundations. The obtained results have allowed determining the typology of foundation and its depth with respect the living surface. In addition, the model of the local geo-stratigraphy was reconstructed, as well as, the geo-mechanical parameters of the litho-types conditioning the foundations structures were determined. Doubts remain on the direct correlation with to crack pattern observed on the Northern façade of the Cathedral.