Geosynthetic encased column-supported embankment: behavior with and without basal geogrid

Abstract

Centrifuge model tests were performed to investigate the beneficial effect of the basal geogrid in improving the performance of geosynthetic encased column (GEC)-supported embankments. The digital image correlation (DIC) technique was adopted to understand the deformation behavior of GEC-supported embankment models. The mobilized tensile strain at various locations on the model basal geogrid was quantified using strain gauge-based instrumentation. The results from the centrifuge test indicate that vertical and lateral displacement of the GECs and surrounding soil has been significantly reduced with the inclusion of basal geogrid in the embankment. Moreover, the differential settlement between the GECs and surrounding soil due to embankment loading were significantly reduced with the inclusion of basal geogrid, thereby the distress in the embankment resting on soft foundation can be avoided. The basal geogrid in the embankment has enhanced the stability of the embankment and improved the load transfer between the GECs and surrounding soil. The maximum mobilized tensile strain in the basal geogrid occurred near the shoulder of the embankment, which indicates the resistance offered by the basal geogrid in preventing the differential settlement between the GECs and surrounding soil.