Coupled hydro-mechanical-chemical model for clay liner

The interconnection among mechanical behaviors of soil, pore water flow and contaminant transport is always involved in the fields of environmental geotechnical engineering and controlling of pollution. The related problems include the construction and maintenance of urban solid waste yards, and the protection of soil and groundwater from pollution. The consolidation deformation of soil is divided into two parts: mechanical consolidation deformation caused by mechanical loading and chemo-osmotic consolidation deformation caused by chemical loading. Then, based on the generalized Darcy’s law and considering dynamic variation of soil physical and transport properties, the coupled hydro-mechanical-chemical model for clay liner is established through theoretical deduction. The remarkable characteristic of the model is that it achieves a full coupling of the consolidation deformation of soil, pore fluid flow and contaminant transport processes. Furthermore, the parameters of the coupled model can also reflect the impacts of coupling effects. The finite element software COMSOL Mutiphysics is adopted to work out the solution of the proposed coupled model and verify its correctness. The numerical results illustrate that the established model can describe the coupled hydro-mechanical-chemical process through inquiring into mechanism., Moreover, the results agree well with those of Peters and Smith. The proposed model can accurately reveal the spatial and temporal distribution of the excess pore water pressure, contaminant concentrations and evolution consolidation deformation of soil.