Smear zone characterization associated with vertical drain installation

In this study the characteristics and extent of the smear zone were investigated using a undisturbed sample. The aim was to capture the realistic characteristics of the smear zone in relation to the in-situ structure of soil during the installation of prefabricated vertical drain (PVD) using a steel mandrel. The extent of the smear zone for Bulli clay was determined on the basis of normalised permeability (kh/khu) and a reduction in the water content upon consolidation. The permeability and compressibility of the soil were investigated to determine the extent to which the soil surrounding the PVD had become disturbed.