PSI - Issue 78

Danilo D’Angela et al. / Procedia Structural Integrity 78 (2026) 1617–1624

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Fig. 2. Statistical pseudo-acceleration spectral responses (Sa) as a function of elastic frequency (f) for analysis loading history sets scaled considering PFA equal to 1.0 g. The loading history sets refer to strong ground motions (SGM) and floor motions (FM), considering far field (FF) and near field (NF) records (D’Angela and Magliulo, 2025) . 2.3. Case studies and engineering demand parameters Ten rigid blocks (RBs) were investigated, referring to small-to-medium (set 1) and medium-to-large (set 2) size elements, with R lower than and larger than 1.5 m, respectively, and also varying block slenderness (h/b); investigated RBs are described in Table 1. RB-1A RB-1B RB-1C RB-1D RB-1E RB-2A RB-2B RB-2C RB-2D RB-2E [m] 0.36 0.72 0.72 0.72 1.43 1.52 3.05 3.05 3.05 4.57 [-] 3.92 1.96 3.92 7.83 3.92 5.00 2.50 5.00 7.50 5.00 [Hz] 4.52 3.20 3.20 3.20 2.27 2.20 1.55 1.55 1.55 1.27 The seismic response of the investigated blocks was assessed considering dimensionless acceleration and velocity engineering demand parameters (EDPs), referring to PGA* and PGV*, respectively, as reported in Equations (4) and (5), respectively. PGA ∗ = g tPaGnA(α) (4) PGV ∗ = g pt aPnG( Vα ) (5) 3. Capacity assessment 3.1. Fragility analysis Seismic capacity was referred to fragility curves (Shinozuka et al., 2000). Fragility curves developed by adopting a lognormal distribution model, following the approach proposed by Porter (Porter et al., 2007). Median fragility R h/b p Table 1. Investigated rigid blocks (RBs) (D’Angela and Magliulo, 2025) . Model ID