Nonlinear Analytical Modeling of Vertical Drain-Installed Soft Soil Considering a Varied Discharge Capacity

Discharge capacity is one of the important factors affecting the consolidation behavior of vertical drains (VDs). Both previous experimental tests and field behavior indicated that the discharge capacity of VDs usually decreased with an increase in effective stress. The aim of this study is to develop a nonlinear analytical solution for consolidation analysis of VD-installed soft deposits considering a reduction of discharge capacity, in which a nonlinear distribution of VD's discharge capacity with depth is adopted. To verify this work, the proposed solution is compared with previous solutions. The analyzed results show that at a given time and depth, the consolidation rate in the case of discharge capacity with a nonlinear distribution is lower than that of a linear and constant distribution. The proposed solution is then applied to a real embankment on the VD-installed thick soft ground in Busan New Port. It is shown that the proposed solution using the nonlinear distribution of VD discharge capacity provides a good agreement with the field data.