Abstract
A new simple method for estimating the amplitude-dependent site amplification factor (that takes soil nonlinearity into account) is developed with the objective of precisely predicting ground motions for seismic hazard analysis. Amplitude-dependent amplification factor is simply calculated from one ground parameter, AVS30 or Sn-value obtained from SPT N-value, and the ground motions on reference bedrock derived from existing attenuation relationship. The ground motion indexes for the amplification factor are PGA, PGV, and 5%-damped acceleration response spectra. The proposed method leads to a reduction of the variability of the observed records compared to the conventional method that does not incorporate amplitude dependency.
