A Three-Dimensional Model Coupled MechanicalConsolidation and Contaminant Transport

Contaminant transport is a common process for a waste disposal site,which is a practical concern in geo-environmental field. It is essential to study the contaminanttransport behavior in impermeable clay liner. Considering the anisotropy ofa clay barrier in permeability, a three-dimensional model coupled mechanical consolidationand contaminant transport is developed for simulation of contaminant transportthrough a deforming porous medium. This is based on the combination of Biot's theoryand the theory of contaminant transport. Meanwhile, porosity is viewed as a couplingparameter. The influence of soil consolidation deformation and permeability anisotropyon contaminant transport can thus be determined reasonably. Transport equationsare solved by using the finite-element software COMSOL Multiphysics. A parametricstudy has moreover been conducted to understand the influence of contaminant sourcetypes and adsorption modes, including constant contaminated source, attenuation contaminatedsource, linear adsorption, Freundlich adsorption, Langmuir adsorption. Thesimulation results indicate that the permeability anisotropy has a negligible effect oncontaminant transport, adsorption modes have a significant impact on transport depthand range, and the concentration distribution of contaminant with different contaminatedsource types have showed a marked difference.