Static requirement and type’s complexity in the diagnostics phase

The preservation of an historical building, whatever its architectural and/or artistic value, is more appropriate as it is deeper the building knowledge, its development, its materials and constructive techniques. So the preliminary phase of a restoration intervention is the data acquisition, the direct characteristics and conditions recognition of the building and the survey of significant alterations. The reasons that cause these modifications, in great number of cases, are not respectful of the building static efficiency, so its static requirement could be weakened. In fact, a very high percentage of building damages is attributable to these modifications are not always sufficiently respectful of a structural balances consolidated over time. The study focuses on the analysis of the restoration intervention on two trilobate pillars that separate the central space from the presbytery in the Cathedral of Matera, a little city in the southern part of Italy. Through the use of sonic tests - carried out despite the complexity of the shape of a building structural and constructive elements that characterizes these pillars – it was possible to show the effectiveness of the implemented intervention, highlighting its critical points and its weaknesses. The research aims to show how - despite the type complexity of some structural elements of a building - becomes essential an appropriate building knowledge to realize interventions that are able to operate a correct restoration interventions of a building and, at the same time, that it is respectful of its type and material peculiarities.