PSI - Issue 78

Ciro Canditone et al. / Procedia Structural Integrity 78 (2026) 1855–1862

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3. Description of the case study: pre-1919 Italian URM residential archetype A choice was here made to simulate the structural response of a residential URM archetype building, to generalize analysis results to a wider building stock. To this end, CARTIS data (Zuccaro, et al., 2023) was considered. CARTIS is a database that provides mechanical and geometrical characteristics of masonry buildings in Italy, including masonry typologies, building age, size and layout, as well as structural features such as wall thickness, center-distance, presence of arches, vaults and floors. The archetype’s geometry and cross-section views are shown in Fig. 2.

Figure 2. URM archetype first storey (a) and upper storeys (b) plan views. Longitudinal (c) and transverse (d) cross-sections.

With regards to the construction age, this study focuses on historical URM buildings fabricated before 1920, i.e., prior to the use of reinforced concrete. A statistical analysis was carried out in (Buonocunto, et al., 2023), leading to the conclusion that an irregular rough stone masonry can be found in 53% of surveyed buildings, with an average wall thickness equal to 0.75 m and a wall-to-wall center-distance approximately equal to 5 m. Three storeys were considered, for a total building height equal to 11.3 m. A 10.85 × 15.70 m 2 rectangular-shaped plan was hypothesized, and a mixed ceiling system comprising barrel vaults at the first story and timber floors at upper storeys was considered. Material properties were inferred from the Italian Building Code and its Commentary (D.M. 17.01.2018; Circolare n°7, 21.01.2019), with reference to irregularly coursed stone masonry and D55 timber. 4. Modeling techniques: FEM and AEM As previously mentioned, two different numerical modelling strategies are here adopted to simulate the structural response of the archetype building under soil settlement loading. A macro-modelling technique entails the modelling of URM mechanical response via the adoption of an equivalent, distributed plasticity continuum material. Several macro-modelling techniques have been developed in the literature, such as the so-called Total Strain Crack Model (TSCM), based on the works by (Vecchio & Collins, 1986), and the Concrete Damage Plasticity (CDP) model, which is rooted in the studies developed by (Lubliner, et al., 1989; Lee & Fenves, 1998). The latter is here adopted and implemented within the Finite Element software package ABAQUS (2010). The CDP model assumes scalar isotropic damage and addresses multi axial stress-states. As frequently observed within continuum-based methods, this modelling technique is less suitable for large strain and/or displacement analyses such as near-collapse conditions. The AEM, on the other hand, is an explicitly discontinuous numerical technique, based on the premise of structural discretization via rigid cuboids connected via nonlinear springs. System deformability and potential failure modes are, hence, lumped into the contact interfaces, thus making the AEM suitable for large displacement, near-collapse and progressive collapse analysis of URM structural elements and buildings (Malomo & Pulatsu, 2024). Six DOFs (Degrees of Freedom) are considered for each block centroid, and spring strains evaluated based on the differential displacements between adjacent blocks. Axial and tangential spring stiffness, k n and k s , are automatically evaluated and updated based on the nonlinear stress-strain relationships adopted in tension, compression and shear. Within this work, fracture energy-based softening functions, based on the work by (Feenstra & De Borst, 1996), were adopted for