Cyclic Performance of Geogrid Encased Stone Column in Soft Clay Using 3d Discrete-Continuum Coupled Method

Abstract

Geosynthetic-encased stone columns (GESCs) represent an efficient and cost-effective solution for enhancing weak soil foundations. However, the deformation and load-bearing mechanisms of GESC-improved foundations under traffic flow become complicated due to substantial particle movements and soil disruption. To comprehend these complexities, a three-dimensional discrete-continuum coupled numerical model that simulates the behavior of GESC-improved soft soils under traffic loads was developed. The reliability and accuracy of proposed model was validated through experimental data. Insights into particle movement patterns, contact force distributions, and stress transfer mechanisms were provided by microscopic analysis. A significant 51.01% increase in radial stress in floating GESCs (F-GESCs) under cyclic loading compared to static conditions was observed via simulations. The geogrid encasement resulted in a 9.84% increase in the contact force of end-bearing columns after cyclic loading. The particle displacement showed a range of 21% to 56% increase under cyclic loading. Both geogrid encasement and cyclic loads contributed to enhanced compaction and coordination number of the columns. The maximum radial strain increased by 14.9% and 9.4% under cyclic load for F-GESC and E-GESC, respectively.

Keywords: Cyclic Loading, Geogrid, Stone Column, Discrete Element Method, Finite Difference Method