Reconstructed Overhanging Battlements. Executive Techniques and their Vulnerability in the Stronghold of Arquata del Tronto (Italy)

The stronghold of Arquata del Tronto was heavily damaged by earthquakes in 2016 and it drew the attention of the experts in reinforcing historic buildings. They regarded it as a case study, a predicting model of the failure in employing specific construction elements in fortified architecture, whose geometric and material data were only approximately considered. The overhanging battlement is the most seriously damaged part of the building and has raised particular attention and interest. As often happens in other castles and fortresses, it dates back to the late 19th and even more to the 20th century. A first close examination of the building’s repairs shows how the new additions, whose maintenance is difficult, ended in failure. The additions were inspired by ancient details, but nonetheless they are unreasonable from the point of view of structure and durability: they – and even more the irrational repairs of the last decades – are the principal cause of failure. Material decay – closely linked to circumstances and places – has also played a decisive role. An extensive and rigorous historical research is necessary to find the sources and to evaluate their nature and limits, as well as to relate all information to the building, thus operating in close correlation with the building archaeology, by now a so widespread and consolidated research field. . Jointly, the written documents and the building itself in its historical stratification allow a better analysis of the structural behaviour , an essential step to achieve an effective restoration planning.