An Embankment Stability Analysis Using Finite Element Method Constructed over Soft Consolidating Soil Improved from Lime Columns and Prefabricated Vertical Drains
Abstract
The effectiveness of lime columns to improve stability of embankment constructed on soft consolidating soil is investigated. Along with this, effectiveness of prefabricated vertical drains (PVDs) with lime columns is also compared. Further, combination of lime columns and PVDs is also studied to improve embankment stability on consolidating soil. A numerical study is carried out using two-dimensional plane strain finite element method. To study effectiveness of lime columns on embankment stability, foundation soil settlement, excess pore water pressure and factor of safety for embankment are obtained at various time intervals during consolidation of foundation soil. This study shows, settlement and excess pore water pressure decreases, and factor of safety increases due to provision of lime columns. Also, settlement is lesser, and factor of safety is larger for soil with lime columns compared to soil with PVDs, whereas, excess pore water pressure dissipates faster in soil with PVDs compared to soil with lime columns. This study concludes, compared to PVDs, lime columns are more effective to improve embankment factor of safety and foundation soil settlement, whereas PVDs are more effective in accelerating excess pore water pressure dissipation. lime columns and PVDs combination are observed to be effective to improve all parameters.