Numerical simulation of centrifuge experiments on liquefaction mitigation of silty soils using stone columns

Installation oF Stone Column (SC) is a promising ground improvement technique to mitigate liquefaction hazards in sand stratum. In this study, a three-dimensional (3D) Finite Element (FE) analysis was used to simulate a centrifuge experiment on the mitigation of silty sand strata liquefaction using SC approach. The predicted response of the silty sand and SC matched the experimental data well. The overall site-stiffening effects due to the installed SCs as well as the distributions of the shear stress and shear stress reductions were evaluated. A parametric study was conducted to investigate the effect of the SC permeability and the surface load at the SC zone on the effectiveness of liquefaction mitigation. The results showed that the SCs behaved in a combined shear and flexure mode. Furthermore, the SCs with permeability exceeding a threshold value can dramatically decrease the liquefaction hazard. On the other hand, larger surface load did not prevent soil liquefaction and produced negligible benefits in stiffening. The present study further enhances the current understanding of the effectiveness of SC remediation approaches in the silty sand.