Centrifuge Consolidation Analysis of Slurries and Tailings Using Finite-Element Modeling

Abstract

The geotechnical centrifuge is an efficient alternative to the slurry consolidometer and settling columns for expedited testing of mine tailings and dredged clay slurries, while accurately reproducing the field stress conditions. Existing numerical models for centrifuge consolidation use piecewise linear and finite-difference methods, and are computationally expensive. This study introduces, for the first time, a finite-element formulation for centrifuge finite-strain consolidation. The proposed model accounts for the nonlinearity induced by the hydraulic conductivity, soil compressibility, and acceleration factor variation along the depth of the centrifuge test specimen. The model incorporates the modified Newton–Raphson method and an implicit time integration technique, leading to a significant reduction in the computational expense. The settlement rate curves generated by the proposed model are validated with corresponding experimental data from the literature studies. The computational cost of the proposed model and existing finite-difference based models are compared for centrifuge and normal gravity consolidation testing conditions. Finally, a parametric analysis is presented to show the influence of various parameters on the functional time steps chosen for the finite-element simulations. The model demonstrates computational robustness and is instrumental for parameter estimation through inverse analysis, and prediction of in-field finite-strain consolidation behavior of slurry wastes.