Seismic vulnerability of different in geometry historic masonry towers

In the present paper, a simple predictive approach for the seismic vulnerability of existing masonry towers is proposed evaluating it on a series of “idealized” benchmark cases using different simplified approaches, namely the procedure proposed by the Italian code and pushover conducted with two commercial codes (UDEC and Tremuri). In UDEC the geometry is intentionally idealized into quadrilateral elements with different thickness, in order to properly reproduce the hollow square cross-section. The utilization of a 2D approach drasti-cally reduces the computational effort required in carrying out medium scale systematic com-putations. In Tremuri macro-elements are used, providing very fast predictions as well. Within such simplified frameworks, 16 different cases that can be encountered in practice are critically analyzed, changing two key parameters that proved to be important for the vulnerability determination, namely slenderness and transversal shear cross area. The simplifications introduced in the modelling phase allow for fast sensitivity analyses in the inelastic range and an estimation of the acceleration factor in that range of slenderness that is useful for practical purposes. Simplified formulas fairly representing the obtained seismic vulnerability are also reported and put at disposal to any practitioner interested in a prelimi-nary estimation of the behavior of the towers before doing any calculation. For validation purposes, the results obtained previously by one of the authors by means of refined full 3D Abaqus discretizations on 25 existing towers located in the Northern Italy are also reported. Good agreement between the predictions provided by the simplified method here proposed and previously presented reference data is obtained.