Influence of Granular Soil Constitutive Model when Simulating the Behavior of Geosynthetic Encased Columns

Encasing a granular column with a high strength geosynthetic significantly decreases its lateral displacement and effectively enhances the load carrying capacity of the column. This paper describes the results of three-dimensional finite element analyses that were carried out to simulate the behavior of a single geosynthetic encased column in soft clay using the Mohr Coulomb, extended Drucker-Prager, and Single Hardening constitutive models for the encased granular soil. Existing triaxial test results for loose and dense sands were used to calibrate the constitutive models that were examined in this study. Numerical results show the importance of selecting a constitutive model that accurately captures the volumetric strain response of the encased granular material during application of axial load to the column.