Prefabricated vertical drain (PVD) has been widely used to consolidate soft ground due to its benefits of
low cost and fast consolidation. Even though, the theoretical solution for the PVD improvement has been basically
found out, there are still a lots of parameters need to figure out in order to conduct a design. In addition, determination
and use of parameters estimated from laboratory and practice conditions could be difficult for engineers and designers.
This study focuses on consolidation of reconstituted clay improved with PVD conducted in the laboratory and practical
soft clay improved with PVD applied at the Bangkok International Airport. As a result, the coefficient of consolidation
( h c ) and effect of PVD installation process demonstrated by a ratio of the horizontal coefficient of permeability in
undisturbed zone ( h k ) to the horizontal coefficient of permeability in smeared zone ( s k ). Furthermore, the different
performance between the two conditions has also discussed.