PSI - Issue 44

Gianluca Fagotti et al. / Procedia Structural Integrity 44 (2023) 339–346 4 Gianluca Fagotti et al./ Structural Integrity Procedia 00 (2022) 000 – 000

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with the roads and containment works, in order to coordinate and convey a quick and organized rebuilding with the full regeneration of this iconographic territory’s symbol. Along with the public interventions priority, therefore, the repair and rebuilding of the aggregates, private buildings and places of worship will have to be carried out, through a single recovery program that includes the restoration of public buildings and private residential fabric, simultaneously with the restoration of related infrastructures and underground services. The need to recover Castelluccio di Norcia village as soon as possible with a single program obviously cannot ignore the coordination and the organized action of the total rebuilding of the built complex and its public services, which due to the center’s characteristics and due to their complexity and identity value, they must necessarily be carried out jointly to obtain a quick and synergistic implementation with the restoration of the forma urbis. In order to achieve the village’s overall rebuilding it is essential to carry out some preparatory interventions, in particular the project of urban terraces and support structures, necessary for the consolidation and restoration of the morphology, as well as for the foundations themselves of the aggregates and buildings of cult. 5.1. Terraced platform seismically isolated at the base and underground rooms For the implementation of the unitary Castelluccio’s nucleus rebuilding, it is planned to use the "ground isolation" technique (Mezzi et al. 2022), which consists in the construction of a terraced platform of great surface development, seismically isolated from to the underlying ground through the interposition of seismic isolators, on which the buildings are built according to the configuration provided for in the Implementation Plan.

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Fig. 2. (a) Terraced platform seismically isolated at the base. (b) Three-dimensional model of the intervention.

The isolated terraced platform acts as a support for the elevation of the buildings that will be subsequently rebuilt. The substructure consists of the beams on which the seismic isolators rest and a foundation platform. The reinforced concrete supports of the isolators have a height such as to guarantee an appropriate distance between the intrados of the isolated platform and the extrados of the foundation platform, making the volume accessible for inspection and maintenance of the devices; this space is also useful for hosting the structures serving buildings and public plant networks. Another important element, given the infrastructural nature and the work’s urban dimension, is represented by the possibility of making a part of it visible and open to visitors with the creation of environments and paths of architectural quality open to the outside. Accessibility to the infrastructure is guaranteed by a circular route (also designed for maintenance) and through the creation of multi-purpose vaulted hypogeal spaces. The hypogeum rooms, corresponding to a useful surface of about 400 sqm, will be obtained in an underground portion under the terraced platform thanks to a deepening of the foundation level, with the consequent increase in height of the volume between the foundation and the insulated platform. The underground volumes may be destined for museum or educational spaces and allow visitors access to the structures and devices of the isolation system (Verducci et al. 2021).