In seismic slope stability analyses the single most important input parameter is the ground motion. Time-history selection is a challenging engineering problem since the variability in ground motion characterization is in part due to the complexity of the mechanisms that result in a seismic event taking place and the path and soil conditions from the origin of the seismic event to the location of interest. In this study, the effect of key ground motion parameters to the dynamic response of earthen levees is investigated. Specifically, the effect on the induced cyclic shear stress ratio (CSR) and/or seismically induced Newmark-type, permanent displacements (U) for prescribed sliding surfaces is discussed. Results were obtained by performing 2-D equivalent linear finite element dynamic analyses for a total of 1,000 ground motions. The mean period, Tm, of the ground motion, and the peak ground velocity, PGV, are among the parameters identified by this study as being good indices for seismic levee response. Identifying the parameters that correlate best with the variability in response will allow the formulation of time-history selection criteria for the seismic response of earthen levees
