Numerical study of the influence of liquefiable layer thickness on the seismic response of geosynthetic encased stone column supported embankments

Abstract

Earthquake-induced soil liquefaction is a major cause of embankment failure. To mitigate this hazard, geosynthetic encased stone column (GESC) has gained increasing attention as an effective ground improvement technique for liquefiable soils. By providing additional radial confinement through the geosynthetic encasement, GESC exhibits higher strength and stiffness compared with conventional stone columns, thereby enhancing the stability and deformation resistance of the improved ground. In this study, a three-dimensional numerical model was developed using FLAC3D to investigate the influence of liquefiable layer thickness on the seismic response of GESC supported embankments. The soil and stone columns were simulated using a pressure-dependent multi-yield surface constitutive model, while the geosynthetic encasement was represented by a linearly elastic geogrid element. The results reveal that the liquefiable layer thickness plays a critical role in controlling the seismic performance of GESC supported embankments. A thicker liquefiable layer leads to greater shear deformation within the foundation and larger embankment settlements, as well as higher tensile strains in the geosynthetic encasement, particularly near the bottom of the liquefiable layer. These findings highlight the importance of considering the effect of liquefiable layer thickness in the design of GESC supported embankments to achieve improved seismic stability and deformation control.