PSI - Issue 78

Laura Giovanna Guidi et al. / Procedia Structural Integrity 78 (2026) 2154–2161

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2.2. Description of the case study The case stud is the Building A of the school complex (Fig. 2). It features a quadrangular plan layout and extends over four above-ground levels, reaching a maximum height of 14m. The main block, referred to as Block A, is organized around a large central covered atrium, 30 m× 22 m in size, topped by a steel structure composed of trussed beams and a corrugated metal roof deck (or other metallic material). The atrium also serves as the main connection point between the various volumes that make up the complex. In particular, Block A is connected to the southern block (Block 3) through two suspended walkways located at each floor level. Additionally, a ground-level connection provides access to Block B, which is designated for sports activities and houses the gymnasium facilities.

Fig. 2 Identification of local structural units

The building’s load -bearing system consists of ordinary reinforced concrete (RC) frames (beams and columns). The floor slabs on all levels, including the roof, are made of clay – concrete composite slabs, except above the atrium, where the roof is constructed with a steel structure. Despite its considerable plan dimensions, the building lacks seismic joints. However, for the purpose of seismic modelling and analysis, a functional subdivision into four distinct blocks was adopted. These blocks are ideally separated along the reinforced concrete walkways connecting the various volumes. This modelling approach allows for a more effective structural interpretation and a clearer identification of potential local vulnerabilities. The RC frames are arranged transversely within each block, with main beams varying in cross-section from 30×60 cm to 30×80 cm. Column dimensions increase from the upper floors toward the foundation, ranging from 30×30 cm to 30×80 cm. The structure exhibits a regular elevation profile and a uniform distribution of loads across the frames. In this case, Building A was analyzed through global models developed in two configurations, to evaluate the influence of secondary elements on the overall stiffness and the distribution of horizontal loads. Further details regarding the modeling process, additional specifications on the structural deformability, and the corresponding buckling verifications will be addressed in a separate study. 3. FEM modeling 3.1. Types of models considered in the analysis Given the complexity of the structural layout, the modeling of Building A was developed using three different configurations (Brandonisio and De Luca, 2024): independent three-dimensional models for each of the four blocks