Performance of an embankment improved with DCM column walls beneath the slope considering variability of mechanical properties

Deep Cement Mixed (DCM) column walls, beneath the sloping sides of an embankment increase the stability of the embankment, enhancing the moment resistance and shear resistance against lateral deformations compared to providing isolated DCM columns beneath the sloping sides. Thus DCM wall type improvement is an ideal solution to increase the overall stability of embankments constructed on soft soil deposits. A higher effectiveness can be achieved when the wall panels are perpendicular to the embankment centreline and located in the active zone. According to the literature, the deformations in the foundation are sensitive to the DCM column wall strength. Therefore, variability of DCM soil strength may affect the factor of safety of the embankment. This study investigates the variability dependent performance of an embankment improved with DCM column walls. The investigation was carried out using 2D numerical models developed in ABAQUS/standard finite element programme. The performance of the DCM column wall improved embankment was compared with the embankment improved with different reinforcement conditions. Then the reliability based performance of the embankment improved with DCM column walls was evaluated using 1D probabilistic method. Results clearly demonstrate the significance of variability of column properties on the embankment performance.