Rock decay phenomena and collapse processes in the “Latomiae del Paradiso” in Syracuse (Sicily)

• Geology and geotechnical engineering can help in retracing historical events.
• Decay phenomena have proved to affect the rock mechanical parameters.
• Tensile stresses can reach the material tensile strength increasing the exploitation.
• Stresses, decay and discontinuities lead to progressive roof thinning.
• The reconstruction can be useful for assessment of risk for the cultural heritage.

The Latomiae (origin: Greek latomia, from laas, las stone plus — tomia tomy) del Paradiso in Syracuse are Magna Graecia rock quarries, located in the coastal areas of Southern Italy and internationally renowned for their impressive environment. The few historical technical records do not help clarify the events that led to their current configuration since a series of instability phenomena occurred due to decay processes over time. Through a geotechnical back-analysis, this work highlights the failure phenomena, which may have led to the current configuration of the easterly side of the Latomiae del Paradiso. The back-analysis process was carried out by means of numerical modelling, supported by geological and meso-structural surveys, as well as a mechanical characterization of the rock mass and an extensive bibliographic and archival research. The result of this work highlights that geology and geotechnical engineering can help in retracing historical events that have affected cultural heritage, even if they are not mentioned in the official history. Such a reconstruction can be extremely useful for the prevention and risk assessment for the cultural heritage itself.