Instability of Unsaturated Soil During the Water Infiltration

  • F. OkaEmail author
  • E. Garcia
  • S. Kimoto
Conference paper
Part of the Springer Series in Geomechanics and Geoengineering book series (SSGG, volume 11)


It is known that the unstable behavior of unsaturated soil includes collapses behavior which is due to the decrease of suction as well as the shear failure. In addition, we often meet the numerical instability for the simulation of unsaturated soil during the wetting process. In the present study, we have performed a one-dimensional linear instability analysis for the air-water-soil coupled three-phase viscoplastic material. From the instability analysis of the viscoplastic unsaturated soil subjected to the water infiltration, we have found that the specific moisture capacity, the matric suction and the hardening parameter affect the instability. Then, we have performed numerical simulations of the behavior of unsaturated soil during the water infiltration using a multi-phase coupled elasto-viscoplastic finite element analysis method. The conditions under which the numerical instability occurs during the simulation agree well with the results by linear instability analysis.


Instability Unsaturated soil Numerical analysis 


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Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Department of Civil and Earth Resources EngineeringKyoto UniversityKyotoJapan
  2. 2.Department of Civil EngineeringUniversity of AntioquiaMedellínColombia

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