Effect of Smear Due to Vertical Drains on the Behaviour of Two Embankments Constructed on Soft Clays

This paper describes the methodology to include the effect of smear in the prediction of settlements beneath two embankments stabilized with vertical drains. The extent of smearing around the drains was studied using a detailed analytical formulation developed by the authors and used in conjunction with the finite clement code, CRISP. The smear zone propagation around vertical drains was studied in the laboratory using a large radial drainage consolidometer. The case histories selected in this study include (a) embankment stabilized with vertical sand drains at a Naval Dockyard, Thailand, and (b) embankment stabilized with vertical band drains in soft Muar clay, Malaysia. It may be concluded from this study that the inclusion of smearing improves the settlement predictions significantly. The numerical results indicate that the extent of smearing is mainly dependent upon the magnitude of horizontal permeability and the drain geometry