Consolidation-Induced Solute Transport for Constant Rate of Strain. I: Model Development and Simulation Results

A numerical model, called CSTCRS1, is presented for coupled one-dimensional consolidation and solute transport under constant rate of strain (CRS) loading conditions. The consolidation algorithm accounts for vertical strain, general constitutive relationships, relative fluid velocity, changing compressibility and hydraulic conductivity during consolidation, and an external hydraulic gradient. The solute transport algorithm accounts for advection, dispersion, linear and nonlinear sorption, and equilibrium and nonequilibrium sorption. Soil compressibility is rate-independent and as such CSTCRS1 is more appropriate for less-structured soils. The model is based on a dual-Lagrangian framework that separately tracks the motions of sold and fluid phases. The development of CSTCRS1 is first described, and is followed by verification checks. Numeric examples are then presented to illustrate the effects of initial contamination distribution, transport conditions, applied strain rate, initial specimen height, and drainage and concentration boundary conditions on solute transport for CRS consolidation. (C) 2014 American Society of Civil Engineers.