Parametric Study on Behavior of Soft Ground Reinforced by Stiffened Deep Cement Mixing (SDCM) Columns

A well-researched soft soil improvement method, deep cement mixing (DCM), has been developed into various innovative types of soil mix columns, one of them is the stiffened deep cement mixing (SDCM) column. Numerous full-scale, physical model load tests and numerical models were carried out to study the behavior of soft soils improved by SDCM columns under embankment load. In this paper, numerical models using finite element PLAXIS 3D software are implemented to further investigate the settlement, differential settlement and the load-sharing proportions of foundation system on soft ground reinforced by SDCM columns. Various core pile lengths were inspected, the maximum settlement of the raft foundation could be decreased up to 2.7 times when the length of core pile increased. Furthermore, the load shared by soft ground under the raft decreased 2 times compared to reinforcement with DCM columns only. Besides, the spacing between SDCM columns was also analyzed, a distance of 3 times the column diameter should be applied to minimize the settlement as well as the differential settlement of the raft foundation.