Dynamic Analysis of Geosynthetic-Reinforced Soil (GRS) Slope Under Bidirectional Earthquake Loading

For the past few decades, geosynthetic-reinforced soil slopes (GRS slopes) have been increasingly used in geotechnical, hydraulic and geoenvironmental engineering applications, due to their great earthquake resistance. Near-field strong ground motion usually involves a vertical component, which is very large in some cases. However, existing design guidelines do not provide a clear approach of earthquake resistant design for GRS slopes subjected to combined horizontal and vertical accelerations. In this study, a nonlinear Finite Element procedure was further validated by a centrifuge shaking table test, and then employed to investigate the seismic responses of a GRS slope model considering a large range of bidirectional earthquake loadings, based on a highway project located in Xinjiang. The results showed that the vertical acceleration had a great effect on permanent displacement, if the corresponding horizontal acceleration was large, and it also played an important role on the stiffness and natural resonant frequency of the soil due to soil compaction. There existed good correlations between the earthquake intensity parameter a_rs at the center of gravity of active wedge and seismic responses of the GRS slope after horizontal earthquake loading.