The complexity of the 3D arrangement of stone columns often requires simplifications into 2D models using equivalent strength parameters for design purposes.
This study employs a simple expression to compute the equivalent block strength and investigates its validity by comparing factors of safety from 2D analyses with those from 3D numerical strip models that account for a realistic interaction between stone columns and surrounding soil.
Information of a real dam tailings stabilisation project is used. The modelling is done for three representative embankment sections under varied replacement ratios and soil conditions. Results show that the Shear Strength Reduction (SSR) factors calculated from 3D finite element simulations are in acceptable agreement with the Factors of Safety (FoS) from 2D limit equilibrium methods using equivalent strength, with maximum differences of 5 per cent.
Moreover, an overall agreement was found in the failure mechanisms, which minor differences that can be attributed to the role of stress distribution and soil-column interactions in 3D models. These results confirm the reliability of the equivalent strength approach for practical 2D designs.
First presented at Life of Mine | Mine Waste and Tailings Conference 2025 and available in the conference paper proceedings (Australasian Institute of Mining and Metallurgy).
