Study on the treatment method of soft soil ground by prefabricated vertical drain

Abstract

    Study on the treatment method for soft soil ground by prefabricated vertical drain (PVD) was implemented based on the modeling of consolidating problems by finite element method with plane strain analysis, in which the equivalent value of vertical hydraulic conductivity was derived based on the equal average degree of consolidation under the 1D condition (Chai et al., 2001). Effects of parameters such as PVD's depth, distance, horizontal hydraulic conductivity of soils, smear, and hydraulic conductivity of the smeared soil were found significant when applicable for a case study of Cau Gie-Ninh Binh highway project. The simulation results showed that the degree of consolidation increased when the PVD depth increased, PVD distance decreased, horizontal hydraulic conductivity increased, the smear reduced, and the hydraulic conductivity of the smeared soil decreased. However, when the PVD depth was greater than 15m, the effect was found not significant. The effect was more obvious when the value of horizontal hydraulic conductivity was greater than that of the vertical one.