Behavior of an Embankment with a Reinforced Slope on Column Improved Clay Deposits

A test embankment with a reinforced slope on column improved soft clay deposits was reported and simulated by the finite element analysis (FEA). Reasonable agreement between the field measured results and FEA results was obtained in terms of the surface settlements, lateral displacements, and excess pore water pressures. The field-measured maximum lateral displacement and numerically simulated stress state in the cement deep mixing (CDM) columns indicate the possibility of partial tensile failure/yielding of the column under the toe of the steep slope. These results suggest that to design an embankment with reinforced steep slopes on CDM column improved soft deposits, possible bending failure of the columns should be considered. The results of further numerical investigations indicate that (1) a combination of basal reinforcement and adding an additional row of CDM columns under the toe of the reinforced steep slope (enhancing the ground improvement), and (2) using a CDM column-slab system are possible effective methods for preventing the bending failure of CDM columns.