Probabilistic Amplification Factors for Response Spectra

Abstract

The concept of inelastic response spectra is now well recognized. The inelastic response spectra can be generated from the peak ground motion parameters by employing amplification factors and deamplification factors. The present study aims at generating amplification factors for two ensembles of artificial earthquakes using the actual probability distribution of the peak displacement response of a viscously single‐degree‐of‐freedom system. It is shown that the knee periods of each spectra of the ensemble vary considerably from those of the mean spectra. This results in considerable difference in the amplification factors in the velocity region. The amplification factors determined using the actual probability distribution of the elastic spectra are within 10% of those obtained using the statistical analysis.