Stochastic Characterization of Ground Motion and Applications to Structural Response

Abstract

A parsimonious stochastic seismic ground-motion model is proposed for use in both ground-motion prediction studies and structural response studies. The model captures with at most nine parameters the features of the ground motion which are important for computing dynamic response, including the amplitude and frequency-content nonstationarities of the earthquake. Furthermore, the model can be efficiently used in both simulated and analytical random vibration response studies. An approximate analytical random vibration method is developed to provide insight into the effect of the temporal nonstationarity in both the amplitude and frequency content of ground motion on the response of simple structural models. It is found that the frequency content nonstationarity may significantly affect the response of both linear and softening non-linear structural models.