Modeling the Behavior of Geosynthetic Encased Columns: Influence of Granular Soil Constitutive Model

Abstract

Using a high-strength geosynthetic for encasement of granular columns increases the strength of a given column and improves its stress-displacement response. This paper describes the results from a series of three-dimensional finite-element analyses that were performed to simulate the behavior of a single geosynthetic-encased column in soft clay. To examine the sensitivity of the results to the constitutive model that was used to simulate the behavior of the encased granular soil, analyses were performed using models for the encased soil possessing various levels of sophistication. For each model that was studied, comparative analyses were performed to simulate the behavior of a dense and a loose granular soil within the encasement. The results demonstrate the importance of selecting a constitutive model that accurately captures the shear-induced volume-change behavior of the encased granular soil. Additional findings provide guidance for other researchers seeking to model the behavior of geosynthetic-encased columns and are useful for practitioners looking to enhance their understanding of the performance of different constitutive models for simulating the behavior of similar foundation elements.