Failure Modes for Embankments over Ground Improved with DCM Column Walls beneath the Slope-Paper

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The study examines failure modes of embankments on soft ground improved with deep cement mixing (DCM) column walls beneath the slopes. Two- and three-dimensional finite-element models in ABAQUS were used to assess how wall stiffness, width and spacing affect deformation and stability.<br /><br />Increasing the DCM wall’s elastic modulus reduced lateral movement and shifted the critical deformation point deeper. At lower stiffness, the wall bent under embankment loading; at higher stiffness, bending became negligible and the wall mainly tilted. The transition occurred at approximately 75 MPa in the model. Increasing wall width also reduced lateral deformation and moved the critical point deeper, though reductions became less pronounced as the wall widened. The wall continued to bend across all widths examined.<br /><br />Three-dimensional analyses indicated that embankment loads were effectively transferred to the DCM walls, including at spacings up to 2.6 m. Soil extrusion between walls was not observed, which the authors attribute to interaction between the walls and surrounding natural soil. The two-dimensional models predicted lateral movements reasonably well for the spacing cases studied.<br /><br />Overall, DCM wall stiffness and width strongly influence the embankment’s deformation pattern and critical failure surface. The findings are based on numerical modelling and the assumed soil–wall interaction.

Keywords

embankment stability

deep cement mixing

DCM column walls

soft ground

finite element analysis

ABAQUS

wall stiffness

lateral deformation

soil-structure interaction

numerical modelling