“Maia” Condominium (Italy)

The building has a resi-stent reinforced concrete frame scheme with a rectangular floor plan (27.90×12.20 m) and development of 6 floors above ground. During the earthquake of 06.04.09, the building suffered major structural damage (class E). A geometric survey and a campaign of experimental tests were carried out to determine the mechanical charac- teristics of the concrete and steels. Depending on the amount of data held, an Accurate Knowledge Level (LC3) (confidence factor FC=1) is assumed. The design approach was aimed at comparing the different methods normally adopted for seismic improvement or retrofitting of existing structures: a) Reinforcement of sections and local increase of ductility; b) Insertion of bracing elements; c) Seismic isolation (shear pillars at the base or top; elastomeric or sliding isolators). It was decided to proceed with the seismic isolation solution, which to a greater complexity of execution, compensates with the advantage of not requiring general strengthening operations of the structure in elevation