The survey of damages after recent earthquakes have shown the fragility of masonry
churches against the out-of-plane overturning of the façade. This failure mechanism is
currently analyzed having recourse to a rigid body model, using either limit analysis with
kinematic approach, or dynamic analysis under rocking motion. However, both the
aforementioned methods neglect the interaction with the lateral walls, leading to an
underestimation of the effective structural capacity under seismic action. The main goal of this
work is therefore to investigate the effect of the interlocking between the façade and the
transversal wall and the influence of the quality of masonry in out-of-plane overturning. For
this purpose, a refined model of masonry through a Discrete Element Method is developed,
based on a detailed recognition of masonry units. The acceleration and displacement capacity
are estimated through quasi-static pushover and pulse-based dynamic analyses and compared
to those calculated for the rigid body model. The proposed methodology is then applied to a
sample of three single-nave masonry churches that suffered damages during the 2009 L’Aquila,
Italy earthquake