Effect of leaching on the compressibility of busan clay

Settlement in a soft clay deposit usually increases at leaching process due to weakening of the bonds in the soil skeleton. This paper investigates the effect of leaching on the compressibility of Busan clay. The treated clay samples were prepared by a leaching procedure in the laboratory with distilled water in the oedometer cell chamber. The initial salinity of about 17 g/L in the clay, which was taken from Hwajeon industrial complex area, was decreased to about 3 g/L in 25 days. A series of Constant Rate of Strain tests (CRS tests) were performed to compare the compression characteristics of natural clay specimens and leached clay specimens with the same soil conditions except for salinity. The experimental results showed that the compressibility of Busan clay increased as its salinity decreased. The compression index and the swelling index had increased but the preconsolidation pressure had decreased after leaching. This may be explained by a weakening of the bonds in the soil skeleton due to the leaching.