Simulating Infiltration and Suction Evolution in Unsaturated Soil Slopes

  • J. R. McDougall
  • I. C. Pyrah
Part of the International Centre for Mechanical Sciences book series (CISM, volume 397)


Infiltration has been frequently cited as a trigger for instability in unsaturated slopes. This paper seeks to illustrate how an unsaturated flow model interprets such phenomena and the process of suction evolution by simulating a series of rainfall events infiltrating an idealised homogeneous slope. Numerical moisture profiles indicate that infiltration following the onset of a rainfall event can be characterised in relation to two extreme patterns of infiltration. On the one hand, where rainfall rates are low and initial hydraulic conductivity is high then infiltration occurs with minimal moisture accumulation. In contrast, where infiltration exceeds the ability of the soil to redistribute it then moisture accumulates and infiltration proceeds as a distinct wetting front.


Rainfall Event Unsaturated Soil Soil Suction Unsaturated Hydraulic Conductivity Phreatic Surface 


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Copyright information

© Springer-Verlag Wien 1998

Authors and Affiliations

  • J. R. McDougall
    • 1
  • I. C. Pyrah
    • 1
  1. 1.Napier UniversityEdinburghUK

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