| The study of solute transport in soil is a hot spot in the field of environmental-geotechnical engineering.However,there are few studies on red clay.After conducting several experiments to the red clay in Guilin and Liuzhou,such as soil-water characteristic curve measurement under total suction,mercury injection test,saturated permeability test,unsaturated soil vertical soil column infiltration test,vertical soil column evaporation experiments,the following results have been achieved:(1)The soil-water characteristics of red clay in Guilin and Liuzhou were measured by pressure plate method,filter paper method and saturated salt solution method.The results showed that the substrate suction of Guilin red clay was higher than that of Liuzhou red under the same water content Clay,the former has a stronger ability to hold water,this phenomenon is mainly related to soil mineral composition,physical properties and pore structure.(2)According to the data of pore size distribution obtained by mercury intrusion test,the permeability coefficient of Guilin and Liuzhou red clay is predicted by the capillary bundle model.It is found that the theoretical value is different from the experimental value.The permeability coefficient depends on the average radius r50 of the pore.The results show that when the equivalent radii of Guilin and Liuzhou red clones are predicted by r20 and r30 respectively,the model predictions are in good agreement with the measured values.(3)The migration laws of moisture and solute in Guilin and Liuzhou unsaturated red clays were studied by one-dimensional soil column infiltration and evaporation test.The water movement and solute transport velocity of Guilin red clay under the same conditions were higher than those of Liuzhou red Clay is fast,the corresponding infiltration volume is more than Liuzhou red clay,and solute transport is lagging behind the water movement;evaporation process,Liuzhou red clay dehumidification faster than Guilin red clay. |
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