Prefabricated vertical drains (PVDs) are widely used to accelerate the dissipation of excess pore pressure in soft estuarine deposits in coastal areas under fill surcharge or vacuum preloading. Vacuum preloading can also control any lateral outward movement of the embankment toe, although excessive inward movement must be avoided. An equivalent 2D numerical modelling is proposed as a predictive tool for multi-drain conditions, but unlike a 3D simulation it has a greatly reduced computation burden. A unit cell model incorporating key factors such as the smear effect, vacuum distribution, nonlinear compressibility and permeability, soil disturbance and large-strain geometry, has also been developed. This paper presents selected work at the University of Wollongong on analytical solution for PVD-assisted ground improvement. The model is applied to a case history at Tianjin Port in China and then compared with the numerical result and field measurements.