Behaviour of geosynthetic encased granular columns under vertical and lateral loading

Granular columns installed below the embankments are subjected to combined action of vertical and lateral loading depending on their location. The columns installed near the centerline of the embankments are primarily subjected to vertical loading while those near the toe are subjected to predominant lateral loading. In this paper analyses are carried out separately to analyze the behaviour of geosynthetic encased granular columns (EGC) subjected to vertical and lateral loading. Along with small scale laboratory studies, 3-dimensional slope stability analyses are carried out using FLAC3D software to analyze the behaviour of granular columns in model and prototype scales. From the analyses it is observed that geosynthetic encasement helps in improving the vertical and lateral load carrying capacity of the columns. EGC also helps to mobilize higher factor of safety compared to ordinary granular column. Encasement of column helps to reduce the area replacement ratio, which leads to consumption of lesser quantity of natural resources and better design procedure.