Behaviour of compacted fine-grained soil in a brine environment

The hydraulic conductivity and engineering properties of compacted fine-grained soils change with time when exposed to a 30% NaCl brine environment. The hydraulic conductivity of brine was found to be greater than that of water in soils where the dominant clay mineral was montmorillonite, whereas a soil rich in illite and kaolinite was virtually insensitive to variations in solution composition. Increases in brine hydraulic conductivities were most pronounced in soils high in montmorillonite where sodium was the dominant adsorbed ion. They demonstrated the most labile hydraulic conductivities. Fine-grained soils, high in montmorillonite clay content, were prone to alteration in engineering properties when soaked in a 30% NaCl brine. However, brine soaking had little effect on soils rich in illite–kaolinite.