ABSTRACT
Geosynthetic encased stone column (GESC) has higher strength than conventional stone column due to the radial confinement of geosynthetic encasement. This technology has been used for ground improvement in soft soils. In this study, the shear strength behavior of GESC under direct shear loading was investigated using the three-dimensional finite difference program FLAC3D. The stone column and surrounding soil were modeled using the linearly elastic-plastic Mohr-Coulomb model, and the geosynthetic encasement was characterized using linearly elastic elements with isotropic behavior. The model also considered the interaction between geosynthetic encasement and adjacent soils (i.e., stone column and surrounding soil). The shear stress-strain response and the development of longitudinal and circumferential strains of GESC during the shear process were presented and discussed. Simulation results indicated that the geosynthetic encasement can increase the shear resistance of stone column, and the longitudinal strains of GESC are greater than the circumferential strains under direct shear loading.
