PSI - Issue 44

Gianluca Fagotti et al. / Procedia Structural Integrity 44 (2023) 339–346 6 Gianluca Fagotti et al./ Structural Integrity Procedia 00 (2022) 000 – 000

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demolitions affected almost the whole of the church, with the exception of portions of the perimeter walls and the apse, the whole of the Oratory ’s Sacrament, the gate city’s arch and the bell tower, causing a loss important for the local cultural heritage. The rebuilding of S. Maria Assunta’s Church, severely damaged by the 2016 earthquake, represents a unique opportunity to re-signify, together with the public spaces opposite, the churchyard and the city gate, the most representative centrality of the historic core and its re-foundation as a monument to memory of an indelible event for Castelluccio’s history. The objective of the rebuilding, in fact, is first of all the recovery of life’s spaces, sociality and collective and individual memory that constitute the heart of cultural and landscape identity of places, through the relationship’s recovery of between full and empty spaces and, as far as possible, of ancient materials. 6. The rebuilding of the urban fabric and the aggregates in the keep The Implementation Plan identified the urban core to be rebuilt in the pre-existing volumetric and architectural configuration, according to the provisions of Ordinance no. 110/2020 and the Special Ordinance no. 18/2021. The objectives that the commissioner action intends to pursue in the rebuilding of the inhabited centers damaged or destroyed by the seismic events are the city’s rebirth, understood as the social and economic fabric underlying the urban’s agglomeration life, and the rebulding’s speed, understood as effectiveness and efficiency of physical ’s processes rebuilding of buildings and urban spaces. In order to ensure compliance with these principles, the rebuilding of the forma urbis configuration with a unitary intervention, through the public rebuilding of public and private buildings coordinated with morphology’s restoration of the soil and the configuration of both public and private spaces, represents an innovative solution. The Castelluccio’s portion that will be treated with the "ground isolation" solution is the one represented by the historic center; this, in fact, is also the only possible isolation solution due to the excessive buildings ’ proximity: the construction of a single terraced platformer the entire historic portion of Castelluccio avoids possible lengthening of the construction times deriving from working with independent construction sites relating to individual aggregates, furthermore avoids the criticalities and further interference connected with the construction of support works and terracing. For the plano-volumetric definition of the platform, some guiding criteria have been identified:  definition of the horizontal planes below the minimum height of the buildings;  containment of the number and height of steps (differences in height between horizontals);  minimization of excavation volumes. The isolated platform, thus determined, has a perimeter of about 350 m, a total projection area in plan of about 6500 square meters, covers a difference in height of 24 m and concerns 60 buildings in building aggregates (private aggregates and 2 religious buildings). The seismic actions of the project are determined according to the NTC2018 (D.M. 17.01.2018), according to the basic seismic hazard of the site where the building is located, and are a function of the morphological and stratigraphic characteristics that determine the local response. Furthermore, given the importance of the work, a reference period condition of 200 years must be considered, which is obtained with a nominal life of 100 years and class of use IV; from this follows a return period for seismic action equal to 2475 years. The buildings set up on the isolated platform are characterized by low seismic stresses and must be built with construction techniques and structural arrangements that give them high rigidity, to achieve the appropriate decoupling of the buildings ’ response in elevation, integral with the isolated platform, from that of the ground. In this way the buildings will benefit from the containment of the seismic action, not only during the earthquakes of maximum intensity expected at the site, which mobilize the maximum movements of the isolation devices, even in case of frequent earthquakes of lesser intensity or phases milder than severe earthquakes. These buildings must therefore be verified independently from the platform system, also to guarantee the possibility of being able to intervene individually on each of them, should it subsequently be necessary: this ensures a future possible autonomous design, regardless of the behavior of the insulated platform. The SLV verifications of the buildings in elevation must be conducted, observing the limitations and the prescriptions foreseen for the buildings isolated at the base, considering the most severe condition among the SLD of