Numerical Modeling of One-Dimensional Consolidation Theory in Saturated and Unsaturated Tailings Using the Soft Soil and Hardening Soil Constitutive Models

This study focuses on the numerical modeling of one-dimensional consolidation of filtered copper tailings under saturated and unsaturated conditions using Plaxis2D®. The modeling is based on 1D consolidation curves under saturated conditions and controlled matric suction. The Soft Soil and Hardening Soil constitutive models were employed, incorporating the soil–water characteristic curve (SWCC) to capture hydro-mechanical behavior and volumetric strain. The modeling strategy replicates the loading and drainage conditions of the experimental tests, using a single set of soil parameters to represent the transition from unsaturated to saturated conditions. Axisymmetric simulations were conducted to replicate the geometry of the experimental specimen, considering initial saturation degrees of 60%, 80%, and 99%, followed by the application of vertical stresses ranging from 10 to 3200 kPa. The results demonstrate that the proposed modeling approach accurately represents the compressibility curve for both constitutive models across different saturation levels. This provides flexibility for conducting numerical analyses tailored to specific soil conditions and geotechnical design requirements. Furthermore, modeling allowed for the evaluation of excess pore pressures and their dissipation time under both saturated and unsaturated conditions.