Abstract
The numerical modeling of unsaturated soil processes is becoming more prevalent worldwide. Although numerical modeling is becoming increasingly accepted in geotechnical engineering practice, care must be exercised and improper modeling techniques and procedures must be avoided. Many issues such as nodal resolution and imperfect convergence can result in inaccurate solutions. Unfortunately, analyses of highly nonlinear unsaturated soil flow and slope stability models can significantly increase the modeling time required. As a result, there is a trend to reduce the number of model runs. Results are often presented to client as single model runs or simplistic sensitivity analysis. This paper presents methodologies for applying probabilistic methods to unsaturated soils seepage and slope stability analysis models. The focus is on the application of the alternative point estimate method to practical problems in such a way as to minimize the number of model runs. The demonstration of a successful application to a waste rock pile is presented.
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References
Anderson M, Woessner W (2002) Applied groundwater modeling; simulation of flow and advective transport. Academic Press, New York
Brooks RH, Corey AT (1964) Hydraulic properties of porous media. Hydrology. Paper No. 3, Colorado State University, Fort Collins, Colorado, vol 27
Clemen RT (1996) Making hard decisions. Duxbury Press, US 664 p
El-Ramly H, Morgenstern NR, Cruden DM (2006) Lodalen slide: a probabilistic assessment. Can Geotech J 42:956–968
Fredlund DG, Xing A (1994) Equations for the soil-water characteristic curve. Can Geotech J 31(4):533–546
Fredlund M, Gitirana G, Pham H (2008) A methodology for applying probability theory to unsaturated hydraulic properties as the foundation for seepage analysis, GeoCongress2008, New Orleans, LA, March 9–12
Gitirana GFN Jr (2005) Weather-related geo-hazard assessment for railway embankment stability. Ph.D. Thesis. University of Saskatchewan, Saskatoon, SK, Canada, 403 p
Li KS (1992) Point estimate method for calculating statistical moments. J Eng Mech 118(7):1506–1511
Mualem Y (1976) A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resour Res 12:513–522
Rosenblueth E (1975) Point estimates for probability moments. Proc Natl Acad Sci 72(10):3812–3814
SoilVision Systems Ltd (2010) SoilVision User’s guide—a Knowledgebased System for Geotechnical Engineers.. Saskatoon, SK, Canada
SOILVISION SYSTEMS LTD (2010) SVFLUX—finite element seepage analysis, Users manual, Version 5 (software package) SoilVision Systems Ltd. Saskatoon, Saskatchewan, Canada
SOILVISION SYSTEMS LTD (2004) SVDYNAMIC—finite element slope stability analysis, Users manual, Version 1 (software package) SoilVision Systems Ltd. Saskatoon, Saskatchewan, Canada
van Genuchten MT (1980) A closed form equation predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44:892–898
Wilson GW, Fredlund DG, Barbour SL (1997) The effect of soil suction on evaporative fluxes from soil surfaces. Can Geotech J 34:145–157
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Fredlund, M., Gitirana, G. Probabilistic Methods Applied to Unsaturated Numerical Modeling. Geotech Geol Eng 29, 217–223 (2011). https://doi.org/10.1007/s10706-011-9391-3
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DOI: https://doi.org/10.1007/s10706-011-9391-3