Out-of-plane local mechanisms in masonry buildings. The role of the orientation of horizontal floor diaphragms

A simplified procedure suggested earlier by the authors is herein reviewed in order to highlight the role of the orientation of floor diaphragms, with reference to one of the most recurrent out-of-plane local mechanisms involving frictional resistances. According to this procedure, the upper and lower bounds of the real ultimate load factor are computed by means of the kinematic approach of limit-state analysis. Two cases of the direction parallel and orthogonal to the façade wall are developed and the results of the parametric analysis are then presented as sets of curves. Some numerical results are also compared with the experimental data existing in the literature.