PSI - Issue 78

Livio Pedone et al. / Procedia Structural Integrity 78 (2026) 1609–1616

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building in Italy, i.e. designed for gravity load only and without any “capacity design” principles. Therefore, the struc ture presents the critical structural weaknesses of buildings designed in that period. In this study, the central / interior longitudinal frame is analyzed. Geometrical and reinforcement details of RC members are shown in Fig. 3b. Transver sal reinforcement is φ 6 / 15 (i.e., 6-mm-diameter stirrups at 15 cm) and φ 8 / 15 for beams and columns, respectively. The joint panel presents no stirrups, and the beams’ longitudinal reinforcement consists of plain round bars with hooked ends. Concerning material mechanical properties, the mean concrete cylindrical strength is f ′ c = 14.41 MPa, while the mean steel yield stress is equal to f y = 340.51 MPa.

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Fig. 3: Case study RC building: (a) global view and (b) geometrical details of RC members.

4.2. Simulated earthquake scenario

The post-earthquake scenario is simulated numerically by performing a nonlinear dynamic (time history) analysis (NLTHA) on a two-dimensional (2D) lumped plasticity model using the structural software Ruaumoko (Carr, 2016). This approach is deemed suitable for a proof-of-concept application. Nevertheless, future validation of the framework, considering real case study structures with information on earthquake damage, is needed. For the sake of brevity, the reader is referred to Pedone et al. (2023) for more information on the modelling approach. Operatively, a ground-motion record is selected from the SIMBAD database (Smerzini et al., 2014), namely: 1980 Irpinia Earthquake (waveform ID: 414; earthquake ID: 46, station ID: BGI; Mw: 6.9, epicentral distance 21.79 km; direction: Y, PGA y = 0.13 g). Fig. 4a shows the results of the NLTHA in terms of maximum interstory drift ratios.

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Fig. 4: Simulated earthquake scenario: (a) maximum interstory drift ratios and (b) observed earthquake damage to structural members.

The results show that, due to the absence of capacity design principles, deformation demand is mainly concentrated in the first two stories. To evaluate damage severity, a detailed component-by-component post-processing is performed (Fig. 4b), considering four damage state (DS) thresholds: DS1 (slight damage), DS2 (moderate), DS3 (extensive), and DS4 (complete). For each structural member, DS1 indicates yielding deformation; DS2 and DS3 correspond to 50% and 75% of the ultimate plastic deformation capacity, respectively; DS4 refers to the attainment of ultimate plastic