Equivalent Stationary Motion for Liquefaction Study

Abstract

An equivalent stationary motion model is evaluated for a liquefaction study. This ground motion model transforms a true, nonstationary motion into a segment of a ficticious Gaussian stationary random process. In the liquefaction study, an excitation is further converted into uniform cycles according to Palmgren-Miner criterion. Effective peak acceleration (EPA) is used as an indicator for liquefaction potential of a motion, which is the amplitude of a motion after it is converted into 10 uniform cycles. For 140 earthquake records, EPA are calculated for both the original and the equivalent stationary motions. Close agreements are observed between these two sets of EPA. Thus, the equilavent stationary motion for ground motions provides an attractive tool for use in the evaluation of the risk of liquefaction.