Time-Dependent Behavior of Embankment Resting on Soft clay Reinforced with Encased Stone Columns

Abstract

In this study, the time-dependent behavior of embankment resting on soft clay reinforced with encased stone column (ESC) is examined numerically. A three-dimensional slice model of an embankment resting on reinforced soft clay was developed to examine the influence of the stiffness of encasement material, length of encasement, and floating ESC on the time-dependent response considering various design parameters like generation and dissipation of excess pore pressure, settlement of composite ground, column deformation, and effective stress experienced by columns and surrounding soils. This investigation reveals that the performance of embankment resting on soft clay reinforced with ESC is better than resting on unreinforced soft clay and soft clay reinforced with granular columns without encasement. Apart from strength enhancement, consolidation characteristics of composite ground were also significantly improved by encasing granular columns with geosynthetic material. Moreover, with the increase in the stiffness of encasement, length of ESC, and length of encasement a significant reduction in the generation of excess pore pressure and lateral deformation were noticed. Further, load transfer mechanism, failure pattern, and temporal variation of stress concentration ratio depend on the encasement stiffness, column length, and encasement length.