Influence of Hydraulic Hysteresis on Effective Stress in Unsaturated Clay

A comprehensive program of laboratory testing on a compacted kaolin in a modified triaxial cell was perform to investigate the influence of hydraulic hysteresis on effective stress in unsaturated soils. The test data are presented on a range of constant suction shear tests along wetting and drying paths. The values of effective stress parameter χ at different matric suction were determined using the test results. The effect of hydraulic hysteresis phenomenon on the effective stress was observed. The values of effective stress parameter χ obtained from the experiments were compared with those obtained from the expressions proposed in literature.

Authors:

• Anuchit Uchaipichat

Keywords:

• Unsaturated soils
• Hydraulic hysteresis
• Effectivestress

References:

[1] R. W. Lewis, and B. A. Schrefler, The Finite Element Method in the
Deformation and Consolidation of Porous Media, John Wiley and Sons,
UK, 1987.
[2] Y. Kohgo, M. Nakano, and T. Miyazaki, "Theoretical aspects of
constitutive modelling for unsaturated soils," Soils and Foundations,
Vol. 33, No. 4, 1993, pp. 49-63.
[3] D. C. Sheng, S. W. Sloan, and A. Gens, "Finite element formulation and
algorithms for unsaturated soils. Part I: Theory," International Journal
for Numerical and Analytical Methods in Geomechanics, vol. 27, no. 9,
2003, pp. 745-765.
[4] B. Loret, and N. Khalili, "An effective stress elastic-plastic model for
unsaturated porous media," Mechanics of Materials, vol. 34, 2002, pp.
97-116.
[5] D. Gallipoli, A. Gens, R. Sharma, and J. Vaunat, "An elasto-plastic
model for unsaturated soil incorporating the effects of suction and
degree of saturation on mechanical behaviour," Geotechnique, vol. 53,
no. 1, 2003, pp. 123-135.
[6] A. W. Bishop, The Principle of Effective Stress, Teknish Ukebladk,
Norway, 1959, pp. 859-863.
[7] J. D. Coleman, "Stress-strain relations for partly saturated soils,"
Geotechnique, Vol. 12, No. 4, 1962, pp. 348-350.
[8] N. Khalili, F. Geiser, and G. E. Blight, "Effective stress in unsaturated
soils, a review with new evidence," International Journal of
Geomechanics, vol. 4, no. 2, 2004, pp. 115-126.
[9] J. W., Hilf, An Investigation of Pore Pressure in Compacted Cohesive
Soils, Technical Memorandum 654. Denver, CO: US Bureau of
Reclamation, 1956.
[10] D. G., Toll, The Behaviour of Unsaturated Compacted Naturally
Ocurring Gravel, PhD Thesis, The University of London, Imperial
College of Science and Technology, London, UK, 1988.
[11] Y. J. Cui, and P. Delage, "Yielding and plastic behavior of an
unsaturated compacted silt," Geotechnique, vol. 46, no. 2, 1996, pp.
291-311.
[12] E. J. Macari, J. K. Parker, and N. C. Costes, "Measurement of volume
changes in triaxial tests using digital imaging techniques," Geotechnical
Testing Journal, Vol. 20, No. 1, 1997, pp. 102-109.
[13] A. Uchaipichat, Experimental Investigation and Constitutive Modelling
of Thermo-Hydro-Mechanical Coupling in Unsaturated Soils, PhD
Thesis, The University of New South Wales, NSW, AUSTRALIA,
2005.