Unsaturated infinite slope stability considering surface flux conditions

Quentin B. Travis, Sandra Houston, Fernando A M Marinho, Mark Schmeeckle

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

A slope stability model is derived for an infinite slope subjected to unsaturated infiltration flow above a phreatic surface. Closed form steady state solutions are derived for the matric suction and degree of saturation profiles. Soil unit weight, consistent with the degree of saturation profile, is also directly calculated and introduced into the analyzes, resulting in closed-form solutions for typical soil parameters and an infinite series solution for arbitrary soil parameters. The solutions are coupled with the infinite slope stability equations to establish a fully realized safety factor function. In general, consideration of soil suction results in higher factor of safety. The increase in shear strength due to the inclusion of soil suction is analogous to making an addition to the cohesion, which, of course, increases the factor of safety against sliding. However, for cohesive soils, the results show lower safety factors for slip surfaces approaching the phreatic surface compared to those produced by common safety factor calculations. The lower factor of safety is due to the increased soil unit weight considered in the matric suction model but not usually accounted for in practice wherein the soil is treated as dry above the phreatic surface. The developed model is verified with a published case study, correctly predicting stability under dry conditions and correctly predicting failure for a particular storm.

Original languageEnglish (US)
Article number009007QGT
Pages (from-to)963-974
Number of pages12
JournalJournal of Geotechnical and Geoenvironmental Engineering
Volume136
Issue number7
DOIs
StatePublished - Jul 2010

Fingerprint

Slope stability
surface flux
slope stability
Fluxes
Soils
safety
suction
Safety factor
soil
saturation
cohesive soil
cohesion
shear strength
sliding
Infiltration
Shear strength
infiltration

Keywords

  • Cohesive soils
  • Embankment stability
  • Equilibrium
  • Failures
  • Landslides
  • Limit equilibrium
  • Pore pressure
  • Pore water
  • Pore-water pressure
  • Slope stability
  • Slopes
  • Soil suction
  • Stability
  • Suction
  • Unsaturated flow
  • Unsaturated soils

ASJC Scopus subject areas

  • Environmental Science(all)
  • Geotechnical Engineering and Engineering Geology

Cite this

Unsaturated infinite slope stability considering surface flux conditions. / Travis, Quentin B.; Houston, Sandra; Marinho, Fernando A M; Schmeeckle, Mark.

In: Journal of Geotechnical and Geoenvironmental Engineering, Vol. 136, No. 7, 009007QGT, 07.2010, p. 963-974.

Research output: Contribution to journalArticle

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