Figure 1
Basic pillars for implementation of unsaturated soil mechanics (Fredlund, 2017Fredlund, D.G. (2017). Role of the soil-water characteristic curve in unsaturated soil mechanics. In Proceedings of the 19th International Conference on Soil Mechanics and Geotechnical Engineering (The Blight Lecture, (Honours lecture), pp. 57-80), Seoul.).
Figure 2
Subdivisions of the unsaturated soil zone (Fredlund, 2015Fredlund, D.G. (2015). Relationship between the laboratory soil-water characteristic curves and field stress state. In Proceedings of the Asia-Pacific Conference on Unsaturated Soils, Quilin.).
Figure 3
Components of moisture movement associated with net moisture flux conditions at ground surface (Fredlund, 2015Fredlund, D.G. (2015). Relationship between the laboratory soil-water characteristic curves and field stress state. In Proceedings of the Asia-Pacific Conference on Unsaturated Soils, Quilin.).
Figure 4
Pictorial visualization of the stress state for saturated/unsaturated soil systems.
Figure 5
Typical Jet-Filled manufactured by Soil Moisture Equipment Corporation, California.
Figure 6
Infiltration into an unsaturated soil under steady state conditions with various ground surface moisture fluxes expressed as a ratio of the saturated coefficient of permeability at ground surface.
Figure 7
Pore-water pressure profiles under transient rainfall conditions that are in excess of the saturated coefficient of permeability of the soil (modified from
Zhang et al., 2004Zhang, L.L., Fredlund, D.G., Zhang, L.M., & Tang, W.H. (2004). Numerical study of soil conditions under which matric suction can be maintained. Canadian Geotechnical Journal, 41(4), 569-582. http://dx.doi.org/10.1139/t04-006.
http://dx.doi.org/10.1139/t04-006...
).
Figure 8
Picture of the Po Shan Landslide in Hong Kong in 1972.
Figure 9
Use of chunam in Hong Kong to maintain the stability of slopes.
Figure 10
Net moisture infiltration at the ground surface calculated from weather station data (Fredlund et al., 2012Fredlund, D.G., Rahardjo, H., & Fredlund, M.D. (2012). Unsaturated soil mechanics in engineering practice. New York: John Wiley & Sons.).
Figure 11
Three fundamental unsaturated soil property functions required in saturated/unsaturated soil mechanics.
Figure 12
Basics of the soil-water characteristic curve, SWCC, family of curves (from Klute, 1965Klute, A. (1965). Laboratory measurement of hydraulic conductivity of unsaturated soil. In C.A. Black, D.D. Evans, J.L. White, L.E. Ensminger & F.E. Clark (Eds.), Methods of soil analysis (Monograph, No. 9, Part 1, pp. 253-261). Madison, WI: American Society of Agronomy., 1986Klute, A. (1986). Water retention: laboratory methods. In A. Klute (Ed.), Methods of soil analysis, part 1 – physical and mineralogical methods (pp. 635-662). Madison, WI: American Society of Agronomy.).
Figure 13
Gravimetric soil-water characteristic curve measurements over the entire range of soil suctions (Fredlund, 2019aFredlund, D.G. (2019a). Determination of unsaturated soil property functions for engineering practice. In Proceedings of the African Regional Conference on Soil Mechanics and Geotechnical Engineering (The Jerry Jennings Memorial Lecture), Cape Town.).
Figure 14
Typical shrinkage curve relating changes in volume to changes in water content (
Fredlund, 2019bFredlund, D.G. (2019b). State of practice for use of the soil-water characteristic curve (SWCC) in geotechnical engineering. Canadian Geotechnical Journal, 56(8), 1059-1069. http://dx.doi.org/10.1139/cgj-2018-0434.
http://dx.doi.org/10.1139/cgj-2018-0434...
).
Figure 15
Degree of saturation soil-water characteristic curve,
S-SWCC, calculated over the entire soil suction range using the
w-SWCC and the Shrinkage Curve (
Fredlund, 2019bFredlund, D.G. (2019b). State of practice for use of the soil-water characteristic curve (SWCC) in geotechnical engineering. Canadian Geotechnical Journal, 56(8), 1059-1069. http://dx.doi.org/10.1139/cgj-2018-0434.
http://dx.doi.org/10.1139/cgj-2018-0434...
).
Figure 16
Coefficient of permeability unsaturated soil property function corresponding to the drying
S-SWCC (
Fredlund & Xing, 1994Fredlund, D.G., & Xing, A. (1994). Equations for the soil-water characteristic curve. Canadian Geotechnical Journal, 31(3), 521-532. http://dx.doi.org/10.1139/t94-061.
http://dx.doi.org/10.1139/t94-061...
).
Figure 17
Typical water storage function for an unsaturated soil (
Fredlund, 2019bFredlund, D.G. (2019b). State of practice for use of the soil-water characteristic curve (SWCC) in geotechnical engineering. Canadian Geotechnical Journal, 56(8), 1059-1069. http://dx.doi.org/10.1139/cgj-2018-0434.
http://dx.doi.org/10.1139/cgj-2018-0434...
).
Figure 18
Permeability function for analyzing steady state and unsteady state seepage through an unsaturated soil (Fredlund et al., 2012Fredlund, D.G., Rahardjo, H., & Fredlund, M.D. (2012). Unsaturated soil mechanics in engineering practice. New York: John Wiley & Sons.).
Figure 19
Contours of hydraulic head and the piezometric line under steady state seepage conditions (Fredlund et al., 2012Fredlund, D.G., Rahardjo, H., & Fredlund, M.D. (2012). Unsaturated soil mechanics in engineering practice. New York: John Wiley & Sons.).
Figure 20
Example of the water storage function required when analyzing transient seepage analysis on an unsaturated soil (Fredlund et al., 2012Fredlund, D.G., Rahardjo, H., & Fredlund, M.D. (2012). Unsaturated soil mechanics in engineering practice. New York: John Wiley & Sons.).
Figure 21
Contours of hydraulic head and the piezometric line under unsteady state seepage for 25 days (Fredlund et al., 2012Fredlund, D.G., Rahardjo, H., & Fredlund, M.D. (2012). Unsaturated soil mechanics in engineering practice. New York: John Wiley & Sons.).
Figure 22
Contours of hydraulic head and the piezometric line under unsteady state seepage for 60 days (Fredlund et al., 2012Fredlund, D.G., Rahardjo, H., & Fredlund, M.D. (2012). Unsaturated soil mechanics in engineering practice. New York: John Wiley & Sons.).
Figure 23
Contours of hydraulic head and the piezometric line under unsteady state seepage after 1500 days (Fredlund et al., 2012Fredlund, D.G., Rahardjo, H., & Fredlund, M.D. (2012). Unsaturated soil mechanics in engineering practice. New York: John Wiley & Sons.).
Figure 24
Lecture Notes on Unsaturated Soil Mechanics prepared for the International Society for Soil Mechanics and Geotechnical Engineering in 2019.