Numerical Investigation of the Effects of Ground Motion Characteristics on the Seismic Behavior of Liquefiable Soil

Abstract

The seismic behavior of liquefiable soils can be significantly influenced by many ground motion characteristics. Therefore, it is crucial to identify the ground motion characteristics that have the most significant effects on the seismic behavior of liquefiable soils. In this paper, a series of nonlinear numerical analyses were performed to investigate the influence of ground motion characteristics on the seismic behavior of loose liquefiable soil. The liquefiable soil profiles were built with the same relative densities but different layer thicknesses. In order to clarify the effect of the ground motion characteristics on the liquefiable soil mechanism, soil profiles were subjected to ground motion sets having different characteristics, such as maximum horizontal accelerations, frequency contents, and significant durations. The numerical analyses were performed using the open-source program OpenSees. The results were presented and discussed in terms of peak ground acceleration, amplification ratio, maximum excess pore pressure ratio, maximum shear strain, and maximum lateral displacement. The results indicated that the maximum horizontal acceleration and the frequency content greatly influence the site response behavior of the liquefiable soil. Furthermore, the nonlinear behavior of the soil is more obvious on being subjected to long-duration ground motions as compared to shorter duration ground motions having the same maximum horizontal acceleration. The findings presented in this study could be helpful when analyzing the seismic response of liquefiable soils coupling superstructures.