Mechanism of Cement Deep Mixing and Design Method Improving Soft Ground in Mekong Delta

Abstract

Soil improvement technique for embankment fill is often needed to rapidly improve the strength of the soft ground. In recent years, the cement deep mixing (CDM) method has been commonly used as an alternative to improve the soft soil foundation of embankment. This method is a reasonable solution used for several applications as to treat the soft soil behind the bridge abutment, to minimize settlement and enhance the bearing capacity of soil foundation for a storage tank, to support segmental retaining walls, and to prevent differential settlement between a new embankment over soft soil and existing embankment where the settlement has ceased. The stability of cement column stabilized embankments can be analyzed either by a numerical calculation method such as the finite element method (FEM) or by a limit equilibrium method. The numerical calculation methods require reliable material parameters as determined by field and laboratory tests or in-situ on excavated columns and on the unstabilized soil. Another method considering simplified method is limit equilibrium method. In analysis of this method, the stability of cement column is analyzed by assuming that failure of the cement columns and the soil.