Diagnosi dei dissesti e conoscenza costruttiva dell’edificio: una dialettica produttiva

The diagnosis of damage and the knowledge of a building’s construction history: a fruitful dialectic relationship. The path to understanding a historic artifact involves the contribution of many specialists working alongside the architect responsible for its restoration, well before the development of a conservation project. One of these is the surveyor, who possesses specific field instruments and IT capabilities. However, historical research is sometimes developed independently and its results are forced to fit the final project without having been discussed in a proper debate. When historical research is not self-referencing, it can benefit enormously from the direct observation of a building and the various different construction (and even destruction) phases that have occurred during its history. Nevertheless, even a mechanical interpretation of the current behaviour of a historic building can benefit immensely from research into written documents and detailed surveys of the building. A great deal of information can be gleaned from the interpretation of the cracks and damage that have appeared on the surface or that have been repaired, if these aspects are related to historical records, revealing the building’s relationship with past events (such as earthquakes) and the duration of time-dependent deterioration phenomena. This paper presents a brief survey of Massa Marittima’s clock tower, highlighting the consequences of past improvements, such as the building of the great arched bridge that connected the tower to the Cassero Senese fortress.