Assessing the influence of an inclined base hinge on the seismic response of masonry walls. The case study of the San Giuseppe dei Minimi oratory

Historical buildings often suffer from local seismic damage due to poor connec-tions between structural members, delivering out-of-plane modes. During the rocking motion, debris can accumulate under the wall, at the base hinge, or be-tween the rocking wall and the sidewalls. This phenomenon causes a change of base hinge that must be considered in the non-linear dynamic analysis through a geometric parameter, here introduced. The out-of-plane modes of masonry fa-çades are generally counteracted by common steel ties working as horizontal re-straints. Dissipative ties were recently conceived for the seismic structural pro-tection but so far were used in very few buildings. To fill this gap, the paper develops a parametric analysis on a church façade which is considered as unre-strained or restrained by either traditional or dissipative ties. The change of the base hinge, which is assumed inclined to simulate the debris accumulation, is discussed in the three scenarios.