Settlement and Moisture Movement in Collapsible Soils
Publication: Journal of Geotechnical Engineering
Volume 116, Issue 10
Abstract
The infiltration of ponded water beneath a footing on collapsible soil is monitored. Soil suction, water content, and footing settlement measurements are made. Laboratory infiltration tests are used to predict the extent of wetting in the field. Close agreement between observed and predicted extent of wetting is obtained. The in situ values of soil suction are quite high, corresponding to a pF value of about 5.26 (1,820 m of water) and degree of saturation of about 15%. In response to ponding, the soil suction drops by a factor of about 10 behind the wetted front, but remains high, with pF 4‐4.5 (100‐316 m of water) and degree of saturation averaging about 50%. Laboratory collapse tests show that partial wetting produces only partial collapse, with 50% saturation producing about 85% of full collapse strain for the soil tested. Partial wetting is considered in making footing settlement predictions, and the predicted settlement exceeds the observed settlement by only about 12%. It appears reasonable to expect close agreement, as in this case, when the extent of wetting is known in advance or well‐predicted.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Bond, W. J., and Collis‐George, N. (1981). “Ponded infiltration into simple soil systems: J. The saturation and transition zone in the moisture content profiles.” Soil Sci., 131(4), 202–209.
2.
Houston, S. L., Houston, W. N., and Spadola, D. J. (1988). “Prediction of field collapse of soils due to wetting.” J. Geotech. Engrg., ASCE, 116(1), 40.
3.
McKeen, R. (1988). “Soil characterization using suction measurements.” 25th Proc. the Paving and Transp. Conf., Univ. of New Mexico, Albuquerque, N.M.
4.
Narasimhan, T. N., and Witherspoon, P. A. (1978). “Numerical model for saturated‐unsaturated flow in deformable porous media, 3.” Water Resour. Res., 14(6), 1017–1034.
5.
Pachepsky, Y. A., and Scherbakov, R. A. (1984). “Determination of capillary hydraulic conductivity of soils and its dependence on suction.” J. Hydro., 287–296.
6.
Philip, J. R. (1969). “Theory of infiltration.” Advances in hydroscience, V. T. Chow, ed., Vol. 5, Academic Press, New York, N.Y., 215–296.
7.
Schuh, W. M., Bauder, J. W., and Gupta, S. C. (1984). “Evaluation of simplified methods for determining unsaturated hydraulic conductivity of layered soils.” Soil Sci. Soc. of Am. J., 48(4), 730–736.
8.
Stauffer, F. (1981). “Infiltration into layered soils: Experiments and numerical simulation.” Proc. of Euromech, A. A. Balkema, Delft, The Netherlands.
19.
Talsman, L. (1976). “Infiltration and movement in prolonged ponding.” Australian J. Soil Res., 14(3), 337–349.
10.
Walsh, K. D. (1988). “State of the art review and conceptual analysis of partially saturated flow modelling,” thesis presented to Arizona State University, at Tempe, Ariz., in partial fulfillment of the requirements for the degree of Master of Science.
Information & Authors
Information
Published In
Copyright
Copyright © 1990 ASCE.
History
Published online: Oct 1, 1990
Published in print: Oct 1990
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.