Issue 50

M. Godio et alii, Frattura ed Integrità Strutturale, 50 (2019) 194-208; DOI: 10.3221/IGF-ESIS.50.17 201 α=0 α=0.5 α=1 Figure 4 : Displacement history (left-hand side) and Lissajous diagrams (right-hand side) of top and bottom wall support motions with relative amplitude, Eqn. (11) - Nahanni record (Tab. 1). P ARAMETRIC STUDY parametric study is carried out on the 16 URM wall configurations already used in [32]. The wall configurations (Tab. 2) are obtained starting from the reference configuration, denoted with C0, by changing at a time one of the following parameters: in C1-C4, the elastic modulus of masonry E m ; in C5-C8, the wall thickness t w , determining the height-to-thickness ratio of the wall; in C9-C12, the rounding of the masonry units r b , determining the effective thickness of the walls; in C13-C16, the vertical stress σ v applied to the top support, giving a different overburden ratio O/W, where W is the wall body weight. In [32], 10 incremental dynamic analyses (IDA) were run for each of the 16+1 configurations, by using the records of Tab. 1. In the present study, 4 sets of (16+1) x 10 IDA are run, resulting in 680 IDA in total. Two sets investigate the dynamic wall response when the top and the bottom support motions have the same amplitude but are phase-shifted; for these 2 sets, Eqn. (8) is used for the generation of the input support motions, with β being set to 0.5 and 1. The other two sets investigate the wall response when the top and the bottom supports are in-phase but have different amplitude; in this case, the support motions are generated by using Eqn. (11) setting α equal to 0.5 and 1. In the IDA presented in [32], the input support motions were equal, which corresponds here to the case in which either β is set to 0 in Eqn. (8) or α is set to 0 in Eqn. (11) (c.f. Fig. 3-Fig. 4). -2 -1 0 1 2 -2 -1 0 1 2 -2 -1 0 1 2 -2 -1 0 1 2 -2 -1 0 1 2 -2 -1 0 1 2 A