Modeling criteria for the seismic assessment of existing masonry buildings

Masonry elements modeling criteria and capacity models are useful for a correct numerical simulation. At first, this work refers to the piers and spandrels strength models according to the Italian design code, investigated in a dimensionless form. Then, the paper presents some preliminary results referring to the masonry strength and in-plane floor flexibility influence on the masonry buildings seismic behavior. Nonlinear pushover analyses are conducted on an ideal existing masonry case study, having three floors and assuming three specific masonry strengths and three floor behaviors. The pushover analyses, performed according to the equivalent frame model, show that in the case of poor masonry the response is not influenced by the in-plane floor stiffness, while it affects the response in the case of masonry of good quality. A mixed global failure mechanism is observed in all analyses performed.