3D Finite Element Analysis of Stone Column Behaviour in Layered Soil with Geosynthetic Reinforced Soil Beds

In the present study, a series of three-dimensional numerical analysis has been performed to understand the behaviour of stone column in layered soil and the purpose of using geocell–geogrid as reinforcement in improving the overall performance of the composite system. Results indicate that the performance improvement visibly enhances with an increase in the depth of top layer (H/D) of clay beds. However, the performance improvement is found to be insignificant beyond the depth of top layer equal to 4D. With the provision of geocell–geogrid reinforcement over the top of stone column, the percentage increase in the bearing capacity of encased stone column in layered soil was found to be nearly 166%. Also, the overall increase in load carrying capacity of reinforced composite system was found to be more than 8 times than that of layered clay beds without stone column. Hence, it clearly indicates that the performance of layered clay beds can be improved very effectively with the provision of geocell–geogrid reinforced sand beds over the stone column placed in layered soil system. Further, the load carrying capacity of stone column is greatly influenced by the friction angle of stone aggregates, stiffness of geosynthetics material and the pocket size of geocell.