Performance of Basal Reinforced Deep Mixed Column-Supported Embankment Resting on Soft Soil: A Parametric Study

Basal reinforced deep mixed (DM) column-supported (BRCS) embankments are used for building highway embankments over soft clay with low shear strength and high compressibility. Finite element method is usually employed in numerical modeling to study the behaviour of these embankments. This study conducts a comprehensive exploration of various parameters of BRCS embankments using finite element (FE) analysis. The validation of results of FE analysis are carried out by conducting laboratory model tests. The influencing factors considered in the parametric study are soft soil strength parameters (κ, λ and M), geotextile tensile strength (T), length (l), diameter (d), number of DM column (N) and Young’s modulus (E) of the DM column. The responses studied are settlement of the embankment crest, heaving of toe, lateral deformation of the embankment slope and tension developed in geotextile basal reinforcement. Results show that stress ratio (M) of the soft soil, tensile strength of geotextile (T), diameter (d) of the DM column, number of DM column (N), and Young’s Modulus (E) of DM column are the major parameters affecting the response of BRCS embankment whereas compressibility of soft soil and the length (l) of floating DM column are the minor parameters. In addition, tensile strength (T) of geotextile has the maximum effect on the lateral deformation of the embankment slope.