An iterative linear procedure using frequency-dependent soil parameters for site response analyses

A borehole array data–based approach for conducting 1D site response analyses I: Damping and VS randomization

“…Similarly, Figure 9 suggests that using σ ln V S ≈ 0 . 2 and σ ln V S ≈ 0 . 35 can improve the predictions in TFs and AFs at f / f 0 = 1 , respectively, but lower σ ln V S are more appropriate at other f / f 0 . Based on these results, 1D SRAs with frequency-dependent damping are expected to be better suited to accurately estimate site response, as suggested in previous studies focused on nonlinear 1D SRAs (Assimaki and Kausel, 2002; Huang et al, 2020; Kausel and Assimaki, 2002; Kuo et al, 2021; Meite et al, 2020; Yoshida et al, 2002). Finally, the L1 error patterns for TFs are narrower, whereas they are broader for AFs.…”

Sensitivity of 1-D ground motion predictions to analysis codes and material models using KiK-net vertical arrays

“…However, a recurrent drawback in the EL model is that the soil properties are assumed constant during the entire duration of motions, which in turn gives rise to some inconsistencies in the ground response as the strain amplitude varies greatly over time. To address this issue, a recently developed FDEL method (Meite et al [42]) is also used, using frequency-dependent shear moduli and damping ratios within the iterative equivalent-linear procedure. In this method, the dynamic soil properties are updated according to the frequency content of ground motions, without using artificial shape-fitting parameters to derive the spectral shear strain amplitudes as required in other FDEL methods (Kausel and Assimaki [28], Yoshida et al [69]).…”

“…Case studies have shown that when these FDEL methods are tested over a range of ground motion intensities, they can provide unrealistic predictions, with a substantial amplification of the high frequency components of ground motions [18,70]. A recently developed FDEL formulation has been proposed to update frequency-dependent soil properties according to the spectral signature of ground motions processed and address the shortcomings observed in the previous methods [42].…”

“…In this paper, the performance of 1-D ground response models is evaluated using 60 downhole ground motion records at five stations from the Kiban-Kyoshin network (KiK-net) in Japan. Total stress analyses are performed using four GRA codes, including the EL method, a recently developed frequency-dependent equivalent linear (FDEL) method [42], a NL model computed in OpenSees [41], and a NL model implemented in DEEPSOIL [19]. Parametric GRA are conducted using a range of material curves, discussed in Section 4.1, that are employed in geotechnical engineering practice.…”