The aim of the study is to seek a simple and inexpensive method to prevent the permeability rise of unsaturated clay caused by evaporation process and to raise its imperviousness. Taking Chengdu clay as an example, fo...The aim of the study is to seek a simple and inexpensive method to prevent the permeability rise of unsaturated clay caused by evaporation process and to raise its imperviousness. Taking Chengdu clay as an example, four treatment schemes were tried. Na 2CO 3 could reduce conspicuously the permeability of the saturated clay, but could not limit the permeability rise in the alternate wetting and drying process. NaOH had a similar effect to Na 2CO 3. NaCl could not only decrease the saturated hydraulic conductivity, but could also effectively contain the permeability rise caused by evaporation. CH 3COONa had a similar effect to NaCl. The mechanism of Na 2CO 3, NaOH, NaCl and CH 3COONa decreasing the saturated hydraulic conductivity of the clay is that Na + transformed Ca montmorillonites in the original clay into Na montmorillonites and the transformation reduces the sizes of effective pores and the effective porosity of the clay.展开更多
文摘The aim of the study is to seek a simple and inexpensive method to prevent the permeability rise of unsaturated clay caused by evaporation process and to raise its imperviousness. Taking Chengdu clay as an example, four treatment schemes were tried. Na 2CO 3 could reduce conspicuously the permeability of the saturated clay, but could not limit the permeability rise in the alternate wetting and drying process. NaOH had a similar effect to Na 2CO 3. NaCl could not only decrease the saturated hydraulic conductivity, but could also effectively contain the permeability rise caused by evaporation. CH 3COONa had a similar effect to NaCl. The mechanism of Na 2CO 3, NaOH, NaCl and CH 3COONa decreasing the saturated hydraulic conductivity of the clay is that Na + transformed Ca montmorillonites in the original clay into Na montmorillonites and the transformation reduces the sizes of effective pores and the effective porosity of the clay.
