The ancient Athena temple of Syracure (Sicily): An investigation on structural stability

Some of the most significant architectural works are monumental masonry constructions. Among these, the Cathedral of Syracuse can be viewed as a fundamental element in the cultural heritage of Europe. For the preservation of these monuments it is necessary to assess their durability by taking into account cumulative damage and cracking conditions in the structures. The paper describes the methods used by the authors to determine the conditions of the materials and the crack patterns in the structures of the Cathedral. In particular, the Acoustic Emission (AE) technique was used to evaluate the time dependence of damage and the onset of critical conditions in a pillar, which is part of the vertical load-bearing structures. The achievement of the critical condition is characterised through a single synthetic parameter, the b-value of the Gutenberg-Richter law. The b-value systematically changes during the different stages of the failure process and tends to 1.0 approaching to final collapse. In the present work this behaviour is shown by several AE tests carried out on specimens of different dimensions extracted from the pillar. In addition, these results are compared with the AE data obtained from the in situ monitored pillar.