PSI - Issue 78

Gianluca Fagotti et al. / Procedia Structural Integrity 78 (2026) 2070–2077

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and primary services for the overall reconstruction of the village of Castelluccio and to providing it with the necessary functional autonomy. These works, tailored to the characteristics of the site and the conditions of the built-up area, are designed to prepare and provide the essential elements for the reconstruction of living conditions for individual citizens and the community. The priority public works, included in Annex No. 1 of Special Ordinance No. 18/2021, which are relevant and urgent for the proper planning and protection of the territory and the urban context, consist of: restoration of the main and secondary roads of the residential area, terracing of the residential area, underground utilities of the residential area, creation of public spaces, construction of underground parking lots, pedestrian and safety paths. To complete the priority public works needed to restore the village's liveability and its socio-cultural values, it was also deemed essential to regenerate, or rather, rebuild, the entire building stock, given its structural peculiarities of buildings nestled one atop another and directly connected to the road system and containment works. This will coordinate and facilitate a swift and organized reconstruction, resulting in the full regeneration of this iconic centre of the area. Along with the priority public interventions, the repair and reconstruction of the complexes, private buildings, and places of worship must be undertaken through a single recovery program that encompasses the restoration of public buildings and private residential areas, along with the rehabilitation of the related infrastructure and utilities. The need to rapidly revitalize the village of Castelluccio di Norcia through a single program must, of course, also include consideration for the coordination and organized action of the complete reconstruction of the building complex and its public services. Given the characteristics of the centre and their complexity and identity, these must necessarily be implemented jointly to ensure rapid and synergistic implementation with the restoration of the urban form. To achieve the overall reconstruction of the village, it is essential to carry out some preparatory work, particularly the design of urban terracing and supporting structures, necessary for the consolidation and restoration of the morphology, as well as for the foundations of the aggregates and religious buildings. 3. The special seismic-resistant system The structural solution provided for the reconstruction of the central portion of Castelluccio di Norcia consists of a special base isolation system extended across the entire project area. The technique is called "artificial ground", Martelli et al. (1999), Zhou et al. (2004), sometimes also called "ground (seismic) isolation", and consists of the construction of a single thick slab that rests on isolators located on squat columns that stand out from the foundation slab laying on the ground. Above the isolated slab the new buildings will be constructed, maintaining their original aesthetics, so restoring the historic centre to its original appearance. The trend of the altitudes, with very significant slopes, requires that the isolated plate is stepped and organized in a number of staggered elevations defined in order to satisfy two criteria: (1) to envelop the base elevations of buildings; (2) to limit the height of the steps. This fact represents one of the most problematic and characterizing aspects of the "artificial ground" project (Fig. 1)

Fig. 1. (a) plan view of stepped plate; (b) stepped plate with buildings' aggregates; (c) typical section of the isolated and foundation slabs