Scenario-Based Investigation of the Damage Pattern of the Saints Filippo and Giacomo (Roncole) Church

The Saints Filippo and Giacomo (Roncole) Church, located in Emilia–Romagna (Italy), sustained severe damage during the 2012 Emilia earthquake sequence, with the predominant failure mechanism consisting of the overturning of the main façade. Reproducing this collapse mechanism through numerical analyses is essential for understanding the seismic response of the church and identifying the earthquake scenarios that most closely represent the observed structural behavior. This study presents a scenario-based numerical investigation aimed at reconstructing the damage evolution of the church through nonlinear dynamic analyses. In the absence of direct recordings at the site, a simplified seismic scenario was reconstructed using accelerograms recorded at nearby seismic stations and interpolation procedures based on logarithmic attenuation relationships. A detailed three-dimensional finite element model of the church was developed in Abaqus using the Concrete Damage Plasticity (CDP) constitutive model to simulate the nonlinear behavior of masonry. Multiple seismic input scenarios were considered by varying the earthquake intensity and source-to-site distance. In addition, different masonry mechanical properties were investigated to account for the uncertainty associated with the existing structure. The seismic response was evaluated through nonlinear time-history analyses by examining displacement histories, damage evolution, crack distribution, and residual deformations. Particular attention was devoted to the initiation and progression of the façade overturning mechanism and its correlation with the damage observed after the 2012 earthquake. The comparison between the numerical results and the documented damage patterns enabled the identification of the seismic scenarios that best reproduce the observed structural response, highlighting the influence of both the adopted ground-motion characteristics and the assumed masonry mechanical properties. The proposed methodology provides an effective framework for interpreting earthquake-induced damage in historic masonry churches and for investigating the seismic scenarios responsible for observed collapse mechanisms.