Research on hydraulic properties of clay under landfill leachate

This paper select the tap water, 0.01mol/L,0.03mol/L,0.05mol/L,0.07mol/L CaCl₂ solution, ionic strength of 0.02mol/L of CaCl₂ and KCl mixed solution for the simulated leachate. The permeability test of clay is carried out, and the influence of different types and different concentrations of leachate on the hydraulic properties of compacted clay is analysed under the different vertical pressure. Experimental results show that the concentrations and types of leachate can impact on the permeability of clay to varying degrees.(1) Permeability of clay increases with the concentration of leachate increases in the same type of leachate.(2) With the vertical pressure increasing,the vertical permeability coefficient of clay decreases at the same leachate concentration, the range of permeability coefficient change between 10^-6-10^-7cm/s.(3) The influence of different types of leachate on the hydraulic properties of the clay shows that the permeability coefficient of contaminated soil with CaCl₂ and KCl mixed solution is lager than the contaminated soil with calcium ion concentration of 0.01 mol/L.(4) The sequencing of permeability coefficient: tap water<; 0.01 mol/L CaCl₂ solution<; 0.03 mol/L CaCl₂ solution<; 0.05 mol/L CaCl₂ solution<; 0.07 mol/L CaCl₂ solution.