Non-destructive techniques applied to the pillars of the Syracuse Cathedral in Sicily

The Cathedral of Syracuse was built over different phases on an ancient Greek temple from the 5th cent b.C. modified along the centuries. The pillars of the central nave, obtained cutting the temple cell walls, show a complex situation of damages and repairs. An investigation programme (including sonic, radar, ultrasonic, etc.) has been recently planned, aimed to design the preservation and restoration actions. An accurate geometrical survey of the surface problems and defects allowed the localisation of the most damaged area, suggesting the further control by NDT. The results obtained from the survey were compared to the results of the other type of tests and the elaborated data will implement an analytical model for the study of the seismic vulnerability. The paper presents and discusses the preliminary results of the research carried out by the authors.