Seismic assessment of an existing RC hospital building: study for the rehabilitation with supplemental fluid-viscous dampers

This paper describes a study for the seismic assessment and rehabilitation of an existing RC hospital building using fluid-viscous dampers. The structure, located in Italy, was built in the earlier 70s and it was designed without considering the seismic action. Due to a change in the seismic classification of the territory, the location is now classified as a seismic zone. The building is characterized by eight storey and by an asymmetric “T” shaped plan. The lateral resisting system is made of frames and shear walls in correspondence to stairs and elevators. This structure was analyzed by developing a non-linear model and by applying pushover procedures. The assessment was carried out in the framework of multi-level performance based approach. The adopted retrofit strategy is based on introduction of non-linear fluid-viscous dampers at each storey. Two options were examined for the rehabilitation: introduction of only supplemental dampers and combination of dampers and new RC shear walls. Design of dampers was performed considering the non-linear behaviour of the structure.