PSI - Issue 44

Fabrizio Comodini et al. / Procedia Structural Integrity 44 (2023) 1076–1083 Author name / Structural Integrity Procedia 00 (2022) 000–000

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guaranteeing the total and/or partial continuation of the activities. The intervention strategy is based on the need to limit the interaction with the internal environments as much as possible, guaranteeing the total and/or partial continuation of human activities. The intervention consists of the realization of an external seismic protection system of adequate stiffness “exoskeleton” to increase the global seismic capacity. A higher rate of seismic action will weigh on the exoskeleton so that the actions acting on the existing building do not exceed the performance levels of the structural elements. The general objective is therefore to achieve the activation of the collapse mechanisms of the existing structural elements by levels of seismic demand greater than that of the current state. The adopted exoskeleton system consists mainly of braced steel frames, arranged on the outside of the building near the facades. The exoskeletons are positioned at the external frames in the transverse direction and only in the central areas of the external frames in the longitudinal direction. The external systems are made with large section S355 steel profiles (HE400B and HEB500) and are characterized by high elastic stiffness, at the base they are constrained on a new pile foundation. The steel bracing systems are placed at a net distance of 500 mm from the existing building. The position of the exoskeletons is illustrated in figures 4,5,6 and 7.

Fig. 4. Plan position of the exoskeletons

Fig. 5. Exoskeleton position facade NW

Fig. 6. Exoskeleton position facade SE