Constructing the foundations on saturated soft soils is more likely to be affected by soft clay subsidence. Therefore, in order to increase the consolidation rate in such soils, prefabricated vertical drains are applied to accelerate the soil consolidation and shorten the drainage path. In current research, in order to investigate the layering effect on vertical drains’ performance, a parametric study has been conducted on Heterogeneous Unit Cell (HUC) improved with PVDs using Plaxis 2D. For instance, numerical results show that, by decreasing the drains distance from 4.5 m to 1.5 m the consolidation degree increased from 25% to 73% for the improved HUC in 140 days.
