Finite element modeling of the consolidation behavior of multi-column supported road embankment

A multi-column composite foundation is a new concept utilizing different column types with varying lengths and diameters to support the embankment fill and to mobilize the strength and stiffness of the soil at shallow depths. This study presents the results of finite element analyses using the finite element software PLAXIS to investigate the consolidation behavior of a road embankment constructed on a multi-column composite foundation. The finite element results are calibrated for a period of 200 days. The settlement, horizontal displacement, differential settlement, column axial force, and the development and dissipation of excess pore pressure are presented and discussed in detail. It is concluded that a multi-column composite foundation allows a fast rate of consolidation and significantly increases the embankment stability. A multi-column composite foundation formed by CFG–lime columns is more effective than one formed by SC–lime columns. The CFG–lime columns improve the long-term stability of the embankment because the compression modulus of CFG columns is significantly greater than that of SC columns.