3D INTEGRATED SURVEYS AND STRATIGRAPHIC METHODS FOR A DEEPER UNDERSTANDING OF HISTORICAL BUILDINGS. A CASE-STUDY OF THE FRANCISCAN MONASTERY AND THE IMMACOLATA CHURCH IN TROINA, SICILY

Abstract. The study presents the results of the application of a multidisciplinary methodology for a deeper understanding of historical buildings. 3D integrated surveys and stratigraphic methods can together make it possible to date the principle construction and evolution phases of historical buildings for which a thorough historical documentation does not exist for our time.

The case-study presented involves the Franciscan monastery and adjacent Immacolata church in Troina, which is a small medieval town located in the north-eastern part of Sicily.

The small number of historical records has only allowed for the dating of the monastery's foundation and of a few of transformation phases. Contrarily to this, various markings on the surfaces of the walls indicate rather the presence of numerous construction phases.

The inaccessibility of parts of the internal spaces, as well as the existence of a sharp incline of the road and of very high walls along scant sections of the road, are the reasons for having chosen to carry out a 3D laser-scanning survey campaign. It made it possible to document the overall area and the relationship between the different parts of the complex. The integration between 3D laser scanning and photo-modelling methods made it possible to highlight the details, anomalies, traces and signs of the stratifications over time. The results of this integrated survey were explained in a series of graphic elaborations in support to the following stratigraphic investigation, to put in order the numerous traces discovered.