Issue 46

L.U. Argiento et alii, Frattura ed Integrità Strutturale, 46 (2018) 226-239; DOI: 10.3221/IGF-ESIS.46.21 236 for these parameters are reported in Tab. 6 where the geometric ones have been chosen accounting for the condition  c ≤ min(  b ,  p ). Set Wall t m o p 11 Single-storey 0.5 1/3 12 - 12 Single-storey 1.0 1/3 12 - 13 Single-storey 1.0 1/2 12 - 14 Single-storey 1.0 1 12 - 15 Five-storey 1.0 1/3 150 - 16 Five-storey 1.0 1/3 150 1 17 Five-storey 1.0 1/3 150 8 Table 6 : Sets of values assumed by the parameters of the comparative analysis. Tab. 7 reports the comparison in terms of load factor between the proposed macro-block model and the micro-block model of Orduña [20], highlighting the percentage difference; in Tab. 8, instead, there are the load factors provided by the other macro-block models and the percentage difference with respect to the micro-block model of Orduña [20]. In both cases, the comparison is possible only with reference to a single-storey wall (Sets 11-14), accounted by all the models considered. Multi-storey walls are, in fact, accounted only by the model developed by Speranza [28] and the comparison with the proposed model is reported in Tab. 9 with reference to a five-storey wall, having constant inter-storey height. Looking at the results related to Sets 11 and 12 in Tabs. 7 and 8, it is possible to derive that when t ≤ 1, i.e. for stocky walls, the load factor is mostly not influenced by this parameter. Besides, the load factors obtained from the proposed model (Tab. 7) and the Speranza’s model [28] (Tab. 8) are very close to that of the micro-block model and by the safe side too. Instead, the load factors of the other macro-block models (Tab. 8) provide higher percentage differences with respect to the micro-block model, up to 23% for the model of De Buhan and de Felice [29]. Set Micro-block model [20] Proposed macro-block model %  Var. 11 0.69 0.65 -5.8 12 0.68 0.65 -4.4 13 0.49 0.49 ±0.0 14 0.26 0.26 ±0.0 Table 7 : Micro-block model [20] vs. the proposed macro-block model. Load factors and percentage differences. Set Orduña [20] %  Var. De Buhan and de Felice [29] %  Var. Speranza [28] %  Var. 11 0.75 +8.7 0.53 -23.2 0.67 -2.8 12 0.65 -4.4 0.53 -22.1 0.67 -1.5 13 0.50 +2.0 0.43 -12.2 0.52 +6.1 14 0.25 -3.8 0.31 +19.2 0.27 +3.8 Table 8 : Load factors provided by literature macro-block models and percentage difference with the micro-block model. Set Proposed model Speranza [28] %  Var. 15 0.47 0.52 10.64 16 0.47 0.48 +2.13 17 0.47 0.37 -21.28 Table 9 : Load factors provided by the proposed model and that of Speranza [28] related to Sets 15, 16 and 17.