Field and 3D Numerical Investigations of the Performances of Stiffened Deep Cement Mixing Column-Supported Embankments Built on Soft Soil

This study presents the results of full-scale field tests of embankments supported with wood-cored stiffened deep cement
mixing (SDCM) columns and conventional DCM columns to highlight the superior performances of wood-cored SDCM
column-supported embankment (SCSE) and to confirm that a less stiff material such as wood can be used as a core in SDCM
columns. A further numerical investigation on SCSE performances is conducted. Several effects of SDCMcolumn parameters
(core pile and socket dimensions and spacing), load-transfer platform inclusion, and different core pile materials are considered
and highlighted. Column-supported embankment performances consisting of embankment settlement, differential settlement,
lateral movement, column bending moment, and embankment stability, are detailedly assessed and discussed. Numerical
results indicate that the significant improvements of soil settlement and safety level regarding column bending failure are
obtained for SCSE. However, the differential settlement of SCSE should carefully be considered. Based on cost-effectiveness,
SDCM columns with small diameter core can be used to support embankments if the required deformation is not strict. It is
also recommended that the wood can be used as the core in SDCM columns to support embankments instead of concrete for
saving the column construction cost.