Estimation of Soil–Water Characteristic Curve of Clayey Till Using Measured Pore-Size Distributions
Publication: Journal of Environmental Engineering
Volume 130, Issue 8
Abstract
The soil–water characteristic curve (SWCC) of fine-grained soils is usually determined experimentally. In the design of mine waste covers and landfill liners, the unsaturated hydraulic conductivity function, is often derived theoretically from the measured SWCC. Implicit in these derivations is the transformation of the SWCC to a pore-size distribution (PSD), typically assumed to be constant and monomodal. However, PSD measurements of a clayey till compacted at various water contents after compaction, after flexible-wall permeability testing and before and after SWCC tests show that the PSD of the same material varies significantly under the stated physical conditions. Predictions of the SWCCs using PSDs measured both before and after the SWCC tests significantly underpredicted the values measured. By applying a simple transformation to the PSD to account for the scaling effect from the porosimetry samples (approximately 1 g dry weight) to the SWCC test samples (approximately 200 g dry weight), the predicted SWCCs were found to envelop the measured values. A simple model that simulates the change in PSD during the SWCC test predicted water contents close (1% root mean square error) to the measured SWCCs.
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References
Acar, Y. B., and Olivieri, I. (1990). “Pore-fluid effects on the fabric and hydraulic conductivity of laboratory-compacted clay.” Transportation Research Record 1219, Transportation Research Board, Washington, D.C., 144–159.
Brooks, R. H., and Corey, A. T. (1964). “Hydraulic properties of porous media.” Hydrology Paper No. 3, Civil Engineering Dept., Colorado State Univ., Fort Collins, Colo.
Childs, E. C., and Collis-George, G. N.(1950). “The permeability of porous materials.” Proc. R. Soc. London, 201, 392–405.
Fernandez, F., and Quigley, R. M.(1988). “Viscosity and dielectric constant controls on the hydraulic conductivity of clayey soils permeated with water-soluble organics.” Can. Geotech. J., 25, 582–589.
Fiytus, S. G., Smith, D. W., and Booker, J. R.(1999). “Contaminant transport through an unsaturated soil liner beneath a landfill.” Can. Geotech. J., 36(2), 330–354.
Fredlund, D. G., and Rahardjo, H. (1993). Soil mechanics for unsaturated soils, Wiley, New York.
Fredlund, D. G., and Xing, A.(1994). “Equations for the soil–water characteristic curve.” Can. Geotech. J., 31, 521–532.
Garcia-Bengochea, I., Lovell, W., and Altshaeffl, A. G.(1979). “Pore distribution and permeability of silty clays.” J. Geotech. Eng., 105(7), 839–856.
Hilf, J. W. (1956). “An investigation of pore-water pressure in compacted cohesive soils.” PhD thesis, U.S. Dept. of the Interior, Bureau of Reclamation, Washington, D.C.
Hueckl, T., Kaczmarek, M., and Caramuscio, P.(1997). “Theoretical assessment of fabric and permeability changes in clays affected by organic contaminants.” Can. Geotech. J., 34, 588–603.
Khire, M. V., Benson, C. H., and Bosscher, P. J.(1999). “Field data froma capillary barrier and model predictions with UNSAT-H.” J. Geotech. Geoenviron. Eng., 125(6), 518–527.
Lapierre, C., Leroueil, S., and Locat, J.(1990). “Mercury intrusion and permeability of Louisville clay.” Can. Geotech. J., 27, 761–773.
Leong, E. C., and Rahardjo, H.(1997). “Permeability functions for unsaturated soils.” J. Geotech. Geoenviron. Eng., 123(12), 1118–1126.
Meerdink, J. S., Benson, C. H., and Khire, M. V.(1996). “Unsaturated hydraulic conductivity of two compacted barrier soils.” J. Geotech. Eng., 122(7), 565–576.
Prapaharan, S., White, D. M., and Altschaeffl, A. G.(1991). “Fabric of field- and laboratory-compacted clay.” J. Geotech. Eng., 117(12), 1934–1940.
Simms, P. H., and Yanful, E. K.(1999). “Some insights into the performance of an experimental soil cover near London, Ontario.” Can. Geotech. J., 36, 846–860.
Van Genutchen, M. T.(1980). “A closed form solution for predicting the hydraulic conductivity of unsaturated soils.” Soil Sci. Soc. Am. J., 44, 892–898.
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Information
Published In
Journal of Environmental Engineering
Volume 130 • Issue 8 • August 2004
Pages: 847 - 854
Copyright
Copyright © 2004 American Society of Civil Engineers.
History
Received: Jun 17, 2003
Accepted: Jun 18, 2003
Published online: Jul 15, 2004
Published in print: Aug 2004
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