Associate professor, New Jersey Institute of Technology, Newark, NJ
Lecturer, Open University of Sri Lanka, Colombo,
An experimental study was performed to investigate factors that control the compression index of contaminated soils and to evaluate the applicability of the correlations proposed by Skempton (1944) and Arulanandan et al. (1983) for contaminated soils. The literature search indicated that the compressibility of a soil depends on mechanical as well as physicochemical factors. The addition of chemicals to a soil changes its pore-fluid properties, and causes a change in mechanical and physicochemical factors and hence its settlement characteristics.
Experimental results indicated that the compressibility of the two soils used in this study changed with the type and amount of chemicals in pore fluids. It was also found that the pore fluid viscosity influenced the compressibility of contaminated soils. Both correlations were unable to provide reasonable estimates of the compression indices for contaminated soils.
The electrical properties reflect the changes in physicochemical interactions but not the changes in mechanical factors due to soil contamination. Both mechanical and physicochemical factors control the compressibility and liquid limit of a soil but to a different degree. Therefore, the changes in mechanical factors brought about by changes in the pore fluid viscosities were included in the above correlations as correction factors. With the correction factors, both correlations appear to predict the settlement characteristics of the contaminated soils used in this study.
Paper ID: GTJ10078J