Multi-storey masonry buildings: evaluation of effectiveness of mechanical strengthening

The paper deals with the problem of evaluating the effectiveness of mechanical retrofitting interventions, with the aim of assessing in-plane seismic capacity of unreinforced masonry structures. With reference to two case studies of typical Italian multi-storey masonry buildings, the above evaluations have been obtained by means of two different approaches: limit analysis and non-linear static analysis (Pushover). The aim of this study is to verify the pro and con of examined analyses methods. Moreover, concerning the limit analysis approach, closed formulas of horizontal collapse multipliers - which also account for the mechanical strengthening contribution - have been proposed for the typical in-plane seismic collapse mechanisms of unreinforced masonry walls.