STEEL ORTHOGONAL EXOSKELETONS: for seismic retrofit of existing reinforced concrete and prestressed concrete buildings: design criteria and applications

摘要

Since the '80s of the last century the use of external steel additive structures is considered one of the most suitable techniques developed for seismic retrofit of existing RC structures with low dissipative capacity. This steel structural typology, called exoskeleton, made its first appearance in the early Japanese and American codes dealing with structural rehabilitation issues, which were put in practice by many applications during the years, especially in high seismic hazard areas. Nowadays, its spread is due not only to the capacity of being implemented without interrupting the construction use, but also for the potentiality to be adopted for the integrated retrofit of the building system. In the present work, after a state-of-the art on the main researches and applications on steel exoskeletons, their typological classification and the definition of the key project parameters have been performed. Finally, for illustrative purposes, it has been shown the application of steel exoskeletons to two case studies: the secondary school "G. Parrozzani" in Isola del Gran Sasso, a district of Teramo, and an industrial building located in Mirabello, a district of Ferrara.