A numerical-geometrical methodology to represent out-of-plane mechanisms of unreinforced masonry structures by using pushover analysis

The present work is aimed to present the preliminary results of a numerical-geometrical strategy for both representing and using nonlinear static analysis outcomes. Indeed, the local collapses of structural elements, which typically involve the historical masonry structures, can produce an inaccurate evaluation of the structural performance under seismic loads. To this end, nonlinear static analysis has been used as a tool to detect the out-of-plane failure mechanisms that might occur. The general idea is to take into account an appropriate number of control points strategically where collapse mechanisms might happen. In this framework, in the position of each control point, a sphere having a size proportional to the detected displacement has been defined. A second objective is to highlight the relationship between the architectural survey, performed using Digital Photogrammetry, and the geometric definition of the structural model. The proposed approach is verified by performing numerical simulations conducted to the San Fili Castle of Stignano (RC), located in the south of Italy.