Settlement behavior of embankment on geosynthetic-encased stone column installed soft ground – A numerical investigation

This paper presents the results of a numerical investigation into the settlement behavior of embankment constructed on geosynthetic-encased stone column installed in soft ground. A three-dimensional finite element model was employed to carry out a parametric study on a number of governing factors such as the thickness and consistency of soft ground, the geosynthetic encasement length and stiffness, the embankment fill height, and the area replacement ratio. It is shown among other things that unlike an isolated geosynthetic-encased stone column, full encasement of stone column is necessary to minimize the settlement for the embankment loading condition. Also revealed is that the efficiency of increasing encasement stiffness is construction condition dependent and is maximized for cases with which the stress intensity in the soft ground is larger. Based on the results of this investigation, design charts for use in estimating the maximum settlement and the stress concentration ratio during preliminary design are presented.