Conservation of Cultural Heritage. Evaluation of archaeological digs effect on the degradation of the structures found

The restoration of Archaeological Heritage gives a remarkable importance to the features of formal and material preservation of elements in their context pursuing the enhancement of its value as historical document. The diagnosis phases must be structured in a complete and complex way to find correct methods of digging, considering that the archaeological digs provide a sudden alteration of the equilibrium condition that the underground structures have reached with the filling layers over the centuries, causing degradation phenomena or accelerated deterioration of the unearthed parts. Some studies have shown a pushed aging for stones subjected to saturation and rapid drying cycles, both in terms of lowering mechanical resistance and activation of pathogenic dynamics. Starting from these studies, a laboratory survey has been carried out on samples of Neapolitan yellow tuff aimed at reproducing, at the small scale, the alteration due by digging phases on natural stones. The paper shows the first results of this survey and proposes intervention strategies to ensure preservation criteria during the archeological digging phases, starting from indirect geometric relief of underground structures, including a thermo-igrometric characterization of the soil-artifact system and developing an intervention method for digging and protecting the Archeological Heritage.