Florence: seismic assessment of not-historical masonry buildings population

The city of Florence, whose historic center has been declared a World Heritage Site by UNESCO in 1982, is known all over the world for its historical and artistic heritage. How-ever, more than half of its buildings population was made in the XX century, therefore pre-senting the typical problems and weaknesses proper of pre-normative “recent” construc-tions. The XX century buildings population is made both by RC and masonry constructions. This work deals with the seismic assessment of masonry buildings made in Florence after the II world war. In those decades, in fact, a large number of masonry buildings has been made, both as private and public projects. The public interventions, belonging to housing national projects, were aimed at providing homes for needing citizens; they cover a large number of buildings, all over the town, having similar features and material. In the paper, a brief de-scription of the development of the public housing in Florence has been presented, and some building—types have been assumed to represent the public buildings population. One of this buildings-type has been selected for an evaluation in terms of seismic assessment. To this purpose two case-studies, belonging to the same type, have been considered, and different assumptions, all consistent to the collected information, have been made about their masonry strength, elastic stiffness and floor weight, in order to represent a variety of possible situations compatible with the proposed classification. The seismic assessment of the case-studies has been made by performing a nonlinear static analysis, where the seismic input has been described according to the Italian current Technical Code. The obtained results evidence a safety level lower than expected for new constructions, whose acceptability depends on the model assumptions.