Shallow Slides in Compacted High Plasticity Clay Slopes
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 130, Issue 7
Abstract
Shallow slide failures in embankments constructed of high plasticity clays create costly maintenance problems on highway projects and can threaten the integrity of water-retaining earth structures. This paper investigates the mechanisms of stability degradation that lead to these slope failures. The failure mechanism involves moisture infiltration into the slope surface that leads to decreases in suction and soil shear strength. Both the degree and time rate of strength loss are investigated based on stability and moisture diffusion analyses, respectively. Stability analyses indicate that the failures are associated with destabilizing hydraulic gradients in the pore water, and the suction level at the surface of the slope declines to a limiting suction of about when exposed to moisture. Moisture diffusion analyses indicate that the time rate of strength degradation is controlled by the depth and spacing of desiccation cracks that form in the soil mass and the moisture diffusion properties of the soil. The stability and moisture diffusion models described above were evaluated in light of 34 documented shallow slides in Texas high plasticity clays.
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References
Aubeny, C., Lytton, R., and Tang, D. (2003). “Simplified analysis of unsteady moisture flow through unsaturated soil.” 82nd Annual Meeting of Transportation Research Board, Geology and Properties of Earth Materials, No. 81, 75–82.
Aubertin, M., Ricard, J., and Chapuis, R.(1998). “A predictive model for the water retention curve: Application to tailings from hard-rock mines.” Can. Geotech. J., 35, 55–69.
Brooks, R. H., and Corey, A. T. (1964). “Hydraulic properties of porous media.” Colorado State University Hydrology Paper, No. 3.
Fredlund, D. G., and Rahardjo, H. (1993). Soil mechanics for unsaturated soils, Wiley, New York.
Hamilton, J. M., Daniel, D. E., and Olsen, R. A. (1981). “Measurement of hydraulic conductivity of partly saturated soils.” Permeability and groundwater contaminant transport, ASTM Special Technical Publication 746, T. F. Zimmie and C. O. Riggs, eds., ASTM, 182–196.
Holtz, R. D., and Kovacs, W. D. (1981). An introduction to geotechnical engineering, Prentice-Hall, Englewood Cliffs, N.J.
Kayyal, M. K., and Wright, S. G. (1991). “Investigation of long-term strength properties of Paris and Beaumont clays in earth embankments.” Research Rep. 1195-2F, Center for Transportation Research, Univ. of Texas at Austin, Austin, Tex.
Knight, M. J. (1971). “Structural analysis of selected duplex soils.” doctoral dissertation, Univ. of Melbourne, Melbourne, Australia.
Kovacs, G. (1981). Seepage hydraulics, Elsevier Science, Amsterdam.
Kulhawy, F. H., and Mayne, P. W. (1990). Manual on estimating soil properties for foundation design, prepared by Cornell Univ. for Electric Power Research Institute.
Laliberte, G. E., and Corey, A. T. (1966). “Hydraulic properties of disturbed and undisturbed clays,” ASTM, STP, No. 417.
Lambe, T. W., and Whitman, R. V. (1969). Soil mechanics, Wiley, New York.
Lamborn, M. K. (1986). “A micromechanic approach to modeling partly saturated soils.” Master of Science thesis, Texas A&M Univ., College Station, Tex.
Lawton, B., and Klingenberg, G. (1996). Transient temperature in engineering and science, Oxford Science, New York.
Lytton, R. (1995). “Foundations and pavements on unsaturated soils.” Keynote Lecture, 1st Int. Conf. on Unsaturated Soils, Paris, Vol. 3, 1201–1222.
Lytton, R. (1997). “Engineering structures in expansive soils.” Keynote Address, Proc., 3rd Int. Symp. on Unsaturated Soils, Rio de Janeiro, Brazil.
Mitchell, J. M. (1976). Fundamentals of soil behavior, Wiley, New York.
Mitchell, P. W. (1979). “The structural analysis of footings on expansive soils.” Research Rep. No. 1, K. W. G. Smith and Assoc. Pty. Ltd., Newton, South Australia.
Powers, D. L. (1972). Boundary value problems, Academic, New York.
Rogers, L. E., and Wright, S. G. (1986). “The effects of wetting and drying on long-term shear strength parameters for compacted Beaumont clays.” Research Rep. 436-2F, Center for Transportation Research, Univ. of Texas at Austin.
Skempton, A. W.(1964). “Long-term stability of clay slopes.” Geotechnique, 14(2), 75–101.
Skempton, A. W.(1985). “Residual strength of clays in landslides, folded strata, and the laboratory.” Geotechnique, 35(1), 3–18.
Stark, T., and Duncan, J. M.(1991). “Mechanisms of strength loss in stiff clays.” J. Geotech. Eng., 117(1), 139–154.
Tang, D. (2003). “Simplified analysis of unsteady moisture flow through unsaturated soil.” MS Rep., Texas A&M Univ., Dept. of Civil Engineering.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 130 • Issue 7 • July 2004
Pages: 717 - 727
Copyright
Copyright © 2004 American Society of Civil Engineers.
History
Received: Mar 12, 2003
Accepted: Dec 7, 2003
Published online: Jun 15, 2004
Published in print: Jul 2004
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