A Parametric Study of Deep Mixing Columns and Fibre Reinforced Load Transfer Platform Supported Embankments

Abstract

The ground improvement technique using deep cement mixing (DCM) columns combined with geosynthetic reinforced traditional angular layer as a load transfer platform supported embankments has recently been adopted widely in construction of roads, railways, and highways over soft soils. This modification technique provides a practical and efficient measure for such infrastructure construction projects as it brings significant savings in construction costs and construction time. In this numerical study, a novel ground modification technique utilising fibre reinforced load transfer platform (FRLTP) and DCM columns supported embankment constructed on top of multilayers of soft soils is proposed and investigated based on the finite element method incorporated in PLAXIS. A series of numerical analyses was firstly carried out on the full geometry of a DCM columns supported (CS) embankment reinforced without or with an FRLTP in a two-dimensional plane strain condition. The main objective of this analysis is to examine the effectiveness of the FRLTP inclusion into the CS embankment system in terms of maximum settlement and lateral displacement. Subsequently, an extensive parametric study was conducted to further investigate the influence of the FRLTP thickness on the performance of the CS embankment by comparing the maximum and differential settlements, and the lateral displacement. The numerical results reveal that the embankment with FRLTP inclusion can effectively enhance the total settlement and the lateral displacement of the embankment. The findings of the extensive parametric study reveal that the platform thickness has significant influence on the embankment behavior, especially in improving the total and differential settlements, the rigidity and stability of the embankment, and the more load transfer from the embankment to DCM columns. Meanwhile it significantly minimises the lateral displacement and the embankment loads transferred to soft foundation soils.