关键词: 化学-力学固结, 解吸附, 污染物输运, 扩散

Abstract: Due to waste accumulation and the capping weight of landfill, mechanical consolidation would happen in impervious barrier of the landfill liner under pressure. The chemical consolidation can also happen when the contaminant transports through the barrier. Then, the above effect of soil consolidation would not only induce contaminant advection, but also make the changes of its inherent transport property, such as soil volume and structural transformation. A hydro-chemo-mechanical contaminant transport framework is established, which is based on the mixture theory. It is able to describe systematically the coupling deformation under the hydro-chemo-mechanical effect, the water absorption and desorption, advection and diffusion. The influence of the hydro-chemo-mechanical coupling effect on the inherent transport property is considered with the changing of macroscopic pores. The contaminant transport is simulated using the coupling advection and diffusion flux. Then, the parametric analyses about consolidation load, diffusion-consolidation coefficient, coupling deformable effect, desorption effect and effective osmotic coefficient are progressed. The analyzing results indicate that if the difference between the adsorption water and free water in the soil of the landfill liner is larger, the more adsorption water would be desorbed. However, when the adsorption water is desorbed, the degree of soil consolidation would be changed with the soil characteristic which is hard or soft. If the overlying load is larger, the effect of limiting expansion of the macroscopic pore in the soil is larger. Subsequently, the velocity of contaminant transport would be reduced.

Key words: chemo-mechanical consolidation, desorption, contaminant transport, diffusion