Numerical Study of the Effect of Geosynthetic Encasement on the Behaviour of Granular Columns
Date
2010
Journal Title
Journal ISSN
Volume Title
Publisher
ICE Publishing
Abstract
In very soft soils, the use of granular columns can be restricted due to the lack of
adequate lateral confining pressure. In these conditions, the columns can be encased by a suitable
geosynthetic to provide the required confining pressure and to increase their bearing capacity.
Using a high-strength geosynthetic for confinement not only increases the strength of a granular
column, but also prevents lateral displacement of the column into the very soft surrounding soil.
This paper describes three-dimensional finite element analyses carried out to simulate the behaviour
of a single granular column with and without encasement in a very soft clay using the computer
program ABAQUS. Comprehensive numerical analyses were performed to study the influence of
the geosynthetic stiffness, the friction and dilation angle of the column material, the length of
geosynthetic encasement, the diameter of the column, the length of the column and the coefficient
of in situ lateral earth pressure. Model results show that the stress–settlement behaviour of
granular columns can be significantly improved by encasing them. The stiffness of the encasement
was found to have a major effect on the stress–settlement response of encased columns and their
associated load-carrying capacity. For partially encased columns, the optimum length of encasement
was found to be a function of the stress that is applied to the column.
Description
Final published version
Keywords
Geosynthetics, Granular column, Stone column, Granular pile, Geosynthetic encasement, Soft soil, Finite element analysis
Citation
Khabbazian, M., Kaliakin V. N. & Meehan, C. L. (2010). Numerical study of the effect
of geosynthetic encasement on the behaviour of granular columns. Geosynthetics International 17, No.3, 132–143. [doi: 10.1680/gein.2010.17.3.132]