Coupled Consolidation and Contaminant Transport in Compressible Porous Media

This paper presents an experimental and computational investigation of coupled consolidation and contaminant transport in compressible porous media. Numerical simulations were performed using the CST2 computational model in which a dual-Lagrangian framework is used to separately follow the motions of fluid and solid phases during consolidation. Diffusion and large strain consolidation tests were conducted on composite specimens of kaolinite slurry consisting of an upper uncontaminated layer and a lower layer contaminated with potassium bromide. An assessment of the importance of the consolidation process on solute transport is based on measured and simulated solute breakthrough curves and final contaminant concentration profiles. CST2 simulations closely match the experimental data for several different transport and loading conditions. Both diffusion and consolidation-induced advection made important contributions to solute transport and mass outflow. This study suggests that neglecting to consider transient consolidation effects may lead to significant errors in transport analyses involving soft contaminated clays undergoing large volume change.