Sensitivity analysis of frequency-Dependent soil models based on rational approximation.

The rational approximation of frequency-dependent soil models is a straightforward way to deal with ground parameters variation, once the sum of partial fractions in frequency-domain become a sum of exponentials in time-domain. This work proposes to investigate sensitivity analyses of the frequency-dependent soil model proposed by Alipio and Visacro with respect to frequency and to the dc conductivity, aiming to a rational realization that is actually simpler than the one obtained through a traditional fitting technique, namely, Vector Fitting (VF). Results indicated that a simpler realization is possible using a smaller subset of the poles and residues obtained via VF, without compromising accuracy within the frequency range of interest.