GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.2 GNGTS 2024 Non-Destructve Testng for the conservaton of a cultural heritage: GPR surveying on masonry walls at the Castellina Museum (Norcia, Italy). M. Ercoli 1* , N. Cavalagli 2 , M. Barchi 1 , C. Pauselli 1 , M. Porreca 1 , R. Lupi 3 . 1 Università degli Studi di Perugia, Dip. Fisica e Geologia, Italy. 2 Università degli Studi di Perugia, Dip. Ingegneria Civile ed Ambientale, Italy. 3 Università degli Studi di Perugia, Dip. di Scienze Politche, Italy. The conservaton of historical masonry constructons represents one of the major challenges for scientfc research, especially in the case of monumental buildings with high artstc and cultural values in areas characterized by high seismic hazard. Here, historical buildings are periodically shacked and damaged by strong earthquakes, and have been subjected to restoratons and changes of their original confguraton. By a mechanical point of view, in the last decades the research has been contnuously involved in the development of advanced and efectve methodologies, conventonally invasive, focused to derive a mechanical evaluaton of their statc and dynamic behaviour, as well as on the characterisaton of masonry materials. At the same tme, Non-Destructve Testng (NDT) techniques can be also very useful when the preservaton of such cultural heritages needs to be ensured by reducing the invasive interventons (Santos-Assuncao et al., 2014). GPR is one of the non-invasive techniques providing high-resoluton images of the subsurface, founding wide applicaton in archaeological and civil engineering studies on ancient walls (Ercoli et al., 2016), as well as for masonry wall diagnostcs (Lombardi et al., 2021; Negri and Aiello, 2021). In this work, we have used a Ground Penetratng Radar (GPR) to obtain non-destructve informaton on the internal structure of a historic masonry wall of the Castellina Museum in Norcia city centre, which is currently unusable afer the serious damaging caused by the long-lastng seismic sequence occurred in 2016-2017 (Norcia earthquake sequence, mainshock Mw=6.5, Porreca et al., 2018). We have investgated a wall located at the ground foor of the building, known to be part (the facade) of a previous edifce, the Palazzo del Podestà. On such a masonry wall, standard sonic tests (ST) have been formerly performed on localized areas to investgate the homogeneity degree of the masonry and, to identfy the presence of possible voids, cracks and degraded areas. Such measures aimed to measure the propagaton velocity of sonic waves on a regular grid, in order to obtain velocity maps able highlightng velocity variatons, to be correlated with degraded areas. Based on such pre-existng data, n°25 Common Ofset GPR profles have been collected across the same grid using high frequency antennas (1 GHz and 1.5 GHz), and later processed, aiming to