Seismic vulnerability of churches. First results of the study on three façade typologies

The series of seismic events which have struck the Italian territory have allowed the damage observation for different typologies of unreinforced masonry buildings. In particular, churches are constantly studied because of their high vulnerability observed in seismic prone areas. The façade is one of the most vulnerable structural units, called macro-elements. Up to date, three kinematic mechanisms (overturning of the façade, gable mechanism and in-plane mechanism) have been identified for damage and vulnerability assessment procedures. In this context, this work focuses on the analysis of three façade typologies diffused on the Italian territory. The aim is to evaluate the seismic response of three façade typologies, different for geometry and construction technique, in order to provide a contribution on their seismic vulnerability assessment. The study was performed through non-linear dynamic analyses, recurring to a model constituted of rigid elements connected by springs (RBSM: Rigid Body Spring Model). The RBS-model simulates the out-of-plane behavior and it considers the orthotropic nature of the masonry, assigning phenomenological elastic-plastic laws to the springs.