A Comparative Three-Dimensional Numerical Study on Geosynthetic-Encased Stone Column Groups Under Varying Conditions

Department of Civil Engineering, Chandigarh University 140413 Mohali, Punjab, India

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Published online: 3 August 2026

Abstract

In the last 40 years, ordinary stone columns (OSCs) have gained popularity in improving soft cohesive soils, specifically in providing support to lightly and moderately loaded structures. However, such methods are not very useful for extremely soft soils. To overcome this limitation, geosynthetic-encased stone columns (GESCs) have been developed recently to enhance the performance in very soft soil. The present research paper deals with a comprehensive numerical analysis of full scale GESCs in soft clay installed in groups, performed in PLAXIS 3D software. The analysis investigates variable parameters of GESCs; column diameter (dc), geosynthetic stiffness, column length (Lc), encasement length (Le), undrained shear strength (cu) and angle of internal friction (ϕ) of the stone column material. The Mohr Coulomb model failure criterion was applied on clayey soil and stone columns. The performance of GESCs was evaluated in the terms of ultimate bearing capacity (UBC) and settlement reduction through load settlement plots. A geosynthetic encasement over ordinary stone columns has shown a notable increase in the ultimate bearing capacity. With reference to case floating GESCs, the gain in UBC was 67% and that for end-bearing GESCs was 164% when compared to the clay bed. The results indicate that increased column diameter reduced significant settlement by 40% in the case of OSCs.