On the Applicability of the Standard Response Spectra to the Seismic Hazard Assessment

Resumo

The ground layer response to seismic loading is analyzed in the paper. Two approaches to the site profile behavior are considered: elastic (linear) and viscoelastic (equivalent linear modeling). Four typical soil profiles are taken into account; input peak values are within the range from 0.1 to 0.6g. In all profiles, when ignoring the nonlinear behavior, the calculated impacts are still within the standard response spectrum. When the nonlinearity is taken into account, the pattern is completely different. The standard spectrum is abundantly conservative for high frequencies; meanwhile, it substantially underestimates the level of hazard at low frequencies. Therefore, the shape of standard spectra as a whole does not adequately describe a seismic hazard, especially when the input signal is higher than 0.2g.