Numerical Study of Embankments Supported by Ordinary and Encased Granular Columns in Peat

Highway and railway embankments form a major part of infrastructure in the transportation sector, but often these embankments rest on weak and problematic deposits with low load-bearing capacities and are prone to high settlements. An attempt has been made to study the performance of an embankment constructed over a weak organic deposit, namely, peat with granular columns as foundation elements. Granular columns have provided effective and promising solutions for flexible loading conditions, especially with soft soils. This ground improvement technique along with geosynthetic encasement is used in the numerical study in assessing and comparing the performance of the embankment in relation to stability. Some parametric studies are also conducted by varying the soil properties say cohesion of the in situ deposit, friction angle of granular column, spacing of granular column, etc., to understand the failure mechanism due to slope instability. The findings from the numerical study revealed the improved performance of embankments founded on geosynthetic encased granular columns.