NUMERICAL ANALYSIS OF PREFABRICATED VERTICAL DRAINS IMPROVED SOFT SOIL BENEATH AN EMBANKMENT DURING STAGED CONSTRUCTION

Abstract

This study is concerned with investigating the advantages of using prefabricated vertical drains (PVD) to improve the foundation soft soil under an embankment. PVD combined with staged construction of embankment is considered as a common technique to reduce both the time for full consolidation and the excess pore water pressure. Rocscience Settle 3D software was used to analyze the embankment and the underlying soft soil which is chosen to be at Basra region. The numerical analysis showed that the PVD is very effective in accelerating the consolidation process and increasing the long term stability of the embankment. It is interesting to note that installing the PVD with spacing (1m) leads to a rapid dissipation of most of the excess pore water pressure at the end of each stage. The length of PVD sheets can significantly accelerate the consolidation more than the spacing.