Synthesizing Ensembles of Spatially Correlated Accelerograms

Abstract

A new approach has been proposed for the simulation of ensembles of spatially correlated accelerograms from an equivalent stationary random field model of the design earthquake motion. This is based on the method of stochastic decomposition and the use of a stationary coherency model. Realistic temporal variations in amplitudes and frequency composition have been introduced into the simulated motions by using the phase and duration spectra of recorded earthquake motions. The simulated motions are consistent with the design spectrum in the mean sense. The proposed method has been illustrated by synthesizing accelerograms with widely different characteristics at four stations spaced 100 m apart.