GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 is the vertical elastic design spectrum; is the horizontal elastic design spectrum according to NTC18; is the corrective VH ratio as a function of spectral period. Corrective vh ratio for design The functional shape proposed for the VH ratio (Figure 1) grounds on the analysis of the average spectral shapes of VH ITA18-NESS ground motion model developed by Ramadan et al. (2021), and it takes the following expression: (2) where is the short-period cut-off associated to the zero-period spectral acceleration; and define the period range corresponding to the peak of the VH ratio; , with T C being the upper corner period of the constant spectral acceleration branch of the horizontal elastic design spectrum, is the corner period defining the beginning of the constant branch of the VH ratio at long periods; is the short-period value of the VH ratio, defined as a function of the design horizontal peak ground acceleration a g (with ag in units of g) for the corresponding site class; is the ratio of the peak of the VH ratio with respect to according to the NTC18 site class. The values of for each site class are given in Table 2.