ABSTRACT
From the finite element studies, Rixner et al. (1986) proposed that:
d a bw = +( ) 2 (11)
More recently, Long and Covo (1994) found that the equivalent diameter dw could be computed using an electrical analogue field plotter:
d a bw = +0 5 0 7. . (12)
4.2 Smear zone
The smear zone is created once a PVD is installed using a steel mandrel. Soil hydraulic conductivity
interacting zone
around the PVDs can decrease significantly, which in turn retards the excess pore pressure dissipation rate and the consolidation process. The decrease in soil permeability can be determined by analysing the ratio of average soil permeability in the smear zone and the in-situ horizontal soil permeability (kh /ks). This ratio and the size of smear zone (ds) depend on the soil sensitivity, mandrel shape, installation speed, and the soil macro fabric. These factors can be investigated using large-scale consolidation tests (Indraratna and Redana 1998; Sharma and Xiao 2000). The extent of the smear zone can be determined employing permeability and water content variations (Sathananthan and Indraratna 2006b).
