Soft Clay Treatment with Two Types of Reinforced Stone Columns: A Numerical Study

Stone columns are usually preferred to enhance the engineering behaviour of soft grounds especially in the case of flexible loaded structures such as embankments. When the clays are very soft with undrained shear strength Su ≤ 15 kPa, a lack in performance of stone columns is reported by researchers. In order to enhance the performance of stone columns, a geosynthetic encasement is provided in the form of vertical encapsulation. Alternatively, they can also be reinforced with horizontal disc-type reinforcements. In the present study, numerical analysis using PLAXIS 2D was conducted to study and compare the performance of an embankment with ordinary and two types of reinforced stone columns. The comparison is made in terms of consolidation settlements, pore pressure dissipation and stress sharing between the stone column and surrounding soil and bulging of stone columns. The influence of parameters, namely friction angle of the stone column material, stiffness of geosynthetic on the consolidation settlements and bulging behaviour are also discussed in brief.