Kinematic analysis of façade collapse mechanisms in historic churches: The case of Sorrento (Naples, Italy)

This study investigates the seismic vulnerability of masonry churches located in the municipality of Sorrento, a region of notable architectural heritage within the metropolitan area of Naples. The research is divided into two main phases. The first phase involved a comprehensive survey and systematic cataloguing of all religious buildings within the study area, using CarTiS forms at both the first and second levels. The first-level forms were employed to delineate territorial units and classify churches based on homogeneous architectural typologies, while the second-level forms provided detailed documentation of each building’s structural characteristics. The second phase focused on assessing seismic vulnerability, with particular emphasis on the out-of-plane overturning of main facades, a frequent failure mechanism in masonry churches during earthquakes. A simplified nonlinear kinematic model was utilized, modelling the façade as an isolated masonry panel rotating around a cylindrical hinge at its base. The analysis also incorporated horizontal thrusts exerted by arches and domes on the façade. This methodological framework enables a preliminary yet meaningful evaluation of the seismic safety of the studied churches. The results reveal a strong correlation between façade geometry, slenderness, and seismic vulnerability, offering critical insights into the stability of these elements under site-specific seismic conditions. The findings support the identification of structural weaknesses and inform the development of targeted retrofitting strategies aimed at improving seismic resilience and safeguarding the region’s historic architectural heritage.