Out of Plane Seismic Resistance of Walls: Collapse Mechanisms and Retrofit Techniques

none4Recent earthquake events in Italy have demonstrated that among the possible collapse mechanisms, masonry structures suffer particularly from local out of plane turning of masonry walls. The activation of local collapse mechanisms is mainly due to the height of the walls, the lack of orthogonal wall restraints, or to a roof configuration that does not withstand local flexure of the upper edge of the wall. In recent years in Italy the Civil Protection Agency has promulgated the administrative requirement that every public building owner must determine the safety margin against collapse under seismic motions. There are actually a number of buildings which have already been checked and some initial conclusions can be drawn about the behaviour of complex masonry historic constructions. Among all the possible local failure mechanisms for masonry buildings, the most dangerous and consistent is the turning of masonry walls around the base edge, or the formation of an internal cylindrical hinge in the panel.congresso internazionale con referee - si tiene ogni tre annimixedA. Benedetti; G. Camata; E. Mangoni; F. PugiA. Benedetti; G. Camata; E. Mangoni; F. Pug