PHOTOGRAMMETRY AND MEDIEVAL ARCHITECTURE. USING BLACK AND WHITE ANALOGIC PHOTOGRAPHS FOR RECONSTRUCTING THE FOUNDATIONS OF THE LOST ROOD SCREEN AT SANTA CROCE, FLORENCE

In this research paper photogrammetric techniques have been successfully applied to historic black and white analogic photographs to convey previously inaccessible architectural and archaeological information. The chosen case study for this paper is the Franciscan Basilica of Santa Croce in Florence, Italy. A photogrammetric algorithm has been implemented over a series of b/w negatives portraying the archaeological excavations carried out in the years 1967–1969, after the traumatic flood of the river Arno in 1966 that severely damaged the city centre of Florence and, particularly, the Santa Croce monumental site. The final aim of this operation is to provide solid evidence for the virtual reconstruction of the lost rood screen of the basilica of Santa Croce, the current subject of the PhD research of one of the Authors (Giovanni Pescarmona) at the University of Florence. The foundations that were uncovered during the archaeological excavation in the ‘60s are one of the most important hints towards a convincing retro-planning of the structure. Using advanced photogrammetric techniques, and combining them with LIDAR scanning, it is possible to uncover new datasets that were previously inaccessible for scholars, opening new paths of research. This interdisciplinary approach, combining traditional art-historical research methods and state-of-the-art computational tools, tries to bridge the gap between areas of research that still do not communicate enough with each other, defining new frameworks in the field of Digital Art History.

Localised strain in fissured clays: the combined effect of fissure orientation and confining pressure

This paper reports the main results of an experimental study on the mechanics of intensely fissured natural clays, extending our previous studies on scaly clay from Santa Croce di Magliano. While previous work focused on the influence of the orientation of fissures with respect to the loading direction, the present investigation specifically explores an additional, important variable: the stress level. The combined effect of fissure orientation and confining pressure was studied by setting up a large campaign of plane strain compression experiments, in which different combinations of these two variables were tested. Conventional global stress–strain measurements were complemented by measuring displacement and strain fields through two-dimensional digital image correlation. Such rich information provided a clear and consistent picture of the interplay between fissure orientation and stress level and revealed complex deformation patterns, which cannot be ignored for a proper interpretation of the material response.

THE COMPLEX OF SANTA CROCE IN RAVENNA AS A CASE STUDY: INTEGRATION OF 3D TECHNIQUES FOR SURVEYING AND MONITORING OF A HISTORICAL SITE

Over the last decades, climate change has brought more and more challenges to managers of cultural heritage and researchers. The increasing effects of natural hazards on assets have required the development of a new protocol of techniques and methodologies for the monitoring of Cultural Heritage and the adoption of management plans adapted to the new challenges at every stage of risk management. The work here presented aims at providing an insight of the work undertaken under the framework of the H2020 SHELTER project, to showcase the first steps of the multi-disciplinary research conducted in one of the project’s case studies, the complex of Santa Croce in Ravenna, Italy. The paper provides the presentation of the case study and the description of the surveying activities with some first results, to provide a preliminary assessment of the site criticalities to be addressed in the future activities in the area, in line with the EU project expected outcomes.