Statistical Assessment of Models for Determination of Soil – Water Characteristic Curves of Sand Soils
Creators
Description
Characterization of the engineering behavior of
unsaturated soil is dependent on the soil-water characteristic curve
(SWCC), a graphical representation of the relationship between water
content or degree of saturation and soil suction. A reasonable
description of the SWCC is thus important for the accurate prediction
of unsaturated soil parameters. The measurement procedures for
determining the SWCC, however, are difficult, expensive, and timeconsuming.
During the past few decades, researchers have laid a
major focus on developing empirical equations for predicting the
SWCC, with a large number of empirical models suggested. One of
the most crucial questions is how precisely existing equations can
represent the SWCC. As different models have different ranges of
capability, it is essential to evaluate the precision of the SWCC
models used for each particular soil type for better SWCC estimation.
It is expected that better estimation of SWCC would be achieved via
a thorough statistical analysis of its distribution within a particular
soil class. With this in view, a statistical analysis was conducted in
order to evaluate the reliability of the SWCC prediction models
against laboratory measurement. Optimization techniques were used
to obtain the best-fit of the model parameters in four forms of SWCC
equation, using laboratory data for relatively coarse-textured (i.e.,
sandy) soil. The four most prominent SWCCs were evaluated and
computed for each sample. The result shows that the Brooks and
Corey model is the most consistent in describing the SWCC for sand
soil type. The Brooks and Corey model prediction also exhibit
compatibility with samples ranging from low to high soil water
content in which subjected to the samples that evaluated in this study.
Files
9999749.pdf
Files
(336.4 kB)
| Name | Size | Download all |
|---|---|---|
|
md5:4c8b22c295393d10bc1368f89c094fe7
|
336.4 kB | Preview Download |
Additional details
References
- N. Collis-George, and B. S. Figueroa, "The use of high energy moisture characteristics to assess soil stability," Australian Journal of Soil Research, vol. 22, pp. 349-356, 1984.
- G. D. Aitchinson, "Relationship of moisture and effective stress functions in unsaturated soils," Conference on Pore Pressure and Suctions in Soils, London, pp. 47–52, 1961.
- B. G. Richards, "Behavior of unsaturated soils," In: Lee, I.K. (ed.) Soil Mechanics-New Horizons, pp. 112-157. American Elsevier, 1974.
- M. Khlosi, W.M. Cornelis, D. Gabriels, G. Sin, Simple modification to describe the soil water retention curve between saturation and oven dryness. Water Resour. Res. 42, W11501, 2006. doi:10.1029/2005WR004699.
- D. G. Fredlund, H. Rahardjo, "Soil Mechanics for Unsaturated Soils," John Wiley & Sons Inc., New York, 1993.
- Y. Mualem, "A new model for predicting the hydraulic conductivity of unsaturated porous media," Water Resources Research, vol. 12, no. 3, pp. 513-522, 1976.
- S. L. Barbour, "The soil–water characteristic curve: A historical perspective," Nineteenth Canadian geotechnical colloquium. Can. Geotech. J. 35(5), 873–894, 1998.
- S. Nam, M. Gutierrez, P. Diplas, J. Petrie, A. Wayllace, N. Lu, J. J. Muñoz, "Comparison of testing techniques and models for establishing the SWCC of riverbank soils," Eng. Geol. 110, 1–10, 2009.
- D. G. Fredlund, H. Rahardjo, M. D. Fredlund, "Unsaturated Soil Mechanics in Engineering Practice," John Wiley & Sons Inc., New Jersey, 2012. [10] W. R. Gardner, "Mathematics of isothermal water conduction in unsaturated soils," Highway Research Board Special Report 40 International Symposiums on Physico-Chemical Phenomenon in Soils, Washington D.C., pp. 78-87, 1956. [11] R. Brooks, and A. Corey, "Hydraulic properties of porous media," Hydrology Paper No. 3, Colorado State University, 1964. [12] W. Brutsaert, "Probability laws for pore-size distributions," Soil Sci., vol. 101, pp. 85-92, 1966. [13] M. Tani, "The properties of a water-table rise produced by a onedimensional, vertical, unsaturated flow" (in Japanese with English summary), J. Jpn. For. Soc., vol. 64, pp. 409-418, 1982. [14] C. R. Mckee, and A. C. Bumb, "The importance of unsaturated flow parameters in designing a hazardous waste site," In Hazardous Waste and Environmental Emergencies (Hazardous Materials Control Research Institute National Conference). Houston, TX, Silver Spring, MD, pp. 50-58, 1984. [15] C. R. Mckee, and A. C. Bumb, "Flow-testing coal bed methane production wells in the presence of water and gas," Society of Petroleum Engineers (SPE) Formation Evaluation, Richardson, TX, pp. 599-608, 1987. [16] M. T. Van Genuchten, "A closed-form equation for predicting the hydraulic conductivity of unsaturated soils," Soil Science Society of America Journal, vol. 44, no. 5, pp. 892-898, 1980. [17] N. T. Burdine, "Relative permeability calculations from pore-size distribution data," Trans. Am. Inst. Min. Metall. Pet. Eng. vol. 198, pp. 71-77, 1953. [18] K. Kosugi, "Three-parameter log-normal distribution model for soil water retention," Water Resour. Res. vol. 30, pp. 891-901, 1994. [19] K. Kosugi, "Lognormal distribution model for unsaturated soil hydraulic properties," Water Resources Research, vol. 32, no. 9, pp. 2697-2703, 1996. [20] D. G. Fredlund, and A. Xing, "Equations for the soil-water characteristic curve," Canadian Geotechnical Journal. vol. 31, pp. 521-532, 1994. [21] C. F. Chiu, W. M. Yan, K. V. Yuen, "Reliability analysis of soil–water characteristics curve and its application to slope stability analysis," Eng. Geol. 135-136, 83–91, 2012. [22] E. C. Leong, and H. Rahardjo, "Review of soil water characteristic curve equations," Journal of Geotechnical and Geoenvironmental Engineering, vol. 123, no. 12, pp.1106-1117, 1997. [23] W. M. Cornelis, M. Khlosi, R. Hartmann, M. Van Meirvenne, B. De Vos, "Comparison of unimodal analytical expressions for the soil-water retention curve," Soil Sci. Soc. Amer. J. 69(1), 1902–1911, 2005. [24] W. S. Sillers, D. G. Fredlund, and N. Zakerzadeh, "Mathematical attributes of some soil-water characteristic curve models," Geotechnical and Geological Engineering, vol. 19, no. 3-4, pp. 243-283, 2001. [25] X. Song, M. Yan, H. Li, "The development of a one-parameter model for the soil-water characteristic curve in the loess gully region," Journal of Food, Agriculture and Environment. 11(3-4), 1546-1549, 2013. [26] A. Nemes, M. G. Schaap, F. J. Leij, and J. H. M. Wosten, "Description of the unsaturated soil hydraulic database UNSODA version 2.0," Journal of Hydrology, vol. 251, pp. 151-162, 2001.