Fragility curves computed with parametric numerical analyses for masonry buildings seismic assessment

The aim of this work is to formulate a new approach for deriving parametric fragility curves taking into account different variables. To this scope, strength models regarding masonry piers and spandrels are firstly analyzed and discussed in a dimensionless form, according to the Italian Design Code and its Instructions. Preliminary pushover analyses are performed referred to a case study by varying masonry strength and in-plane floor flexibility. These analyses are conducted with the aim of evaluating the influence on the nonlinear response of masonry elements strength models. Afterwards, a case study with brick masonry and rigid floors is considered, of which a geometric characteristic, slenderness, is varied, referring to both piers and spandrels. Starting from the numerical results obtained with pushover analysis, parametric fragility curves of the case study considered are proposed. Specifically, the variables taken into account for the fragility curves parameterization are the two slendernesses mentioned above and the global one. The variation of these slendernesses affects the trend of the derived fragility curves, then compared with literature and empirical ones.