Investigations regarding soils below phreatic surface as unsaturated porous media

  • Hans-Jürgen Köhler
  • Hector Montenegro
Part of the Springer Proceedings in Physics book series (SPPHY, volume 94)


Submerged soils may be considered as an unsaturated porous medium containing gas, water and solids. By using a three-phase model, the mechanical behaviour of such soils can be described by an extended consolidation equation in order to calculate transient pore water pressures, induced by external pressure changes. Microscopic gas bubbles embedded in the pore fluid of the soil skeleton may play a key role in soil behaviour due to the increased gas-water mixture compressibility. Pressure changes applied on such unsaturated submerged soils may cause soil structure deformations such as heaving, settling or even fluidisation. Rapid external pressure reductions such as excavations, draw down loading or ground water level lowering are followed by a delayed pore water pressure propagation. Transient pore water pressures may therefore cause embankment sliding, hydraulic failure and unacceptable deformation. Case studies concerning geotechnical applications are presented. Results from numerical simulations based on Biot’s consolidation equation are compared with computations based on Richards equation. The results are discussed towards formulation of protection measures in order to improve stability requirements.


Unsaturated Porous Medium Phreatic Surface Pore Water Pressure Propagation Transient Pore Water Pressure Ground Water Level Lowering 
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  1. Bezuijen, A. & Köhler, H.-J., 1998. Filter-and revetment design of water imposed embankments induced by wave and draw down loadings. In: Dikes and Revetment; Design, maintenance and safety assesment, K. Pilarczyk (ed.), (ISBN 9054104554), 1998. A.A. Balkema. Rotterdam, (537–559).Google Scholar
  2. Biot M. E. 1941. General Theory of Three-Dimensional Consolidation. Journal of Applied Physics, Vol. 12, February 1941, New York.Google Scholar
  3. Fredlund D.G. & Rahardjo H., 1993. Soil Mechanics for Unsaturated Soils John Wiley & Sons, Inc.Google Scholar
  4. GGU, 2002. Finite element code, Johann Buß, Braunschweig, Germany.Google Scholar
  5. Köhler, H.-J. & Asami, K., 2002. Draw down and its influence on embankment stability In: Proceedings of the 12th Danube European Conference Geotechnical Engineering (ISBN 3-7739-5973-7), Passau, Germany, 27th–28th May 2002, Deutsche Gesellschaft für Gerotechnik e.V. (DGGT) (ed.), Verlag Glückauf GmbH (VGE), Essen, (181–184).Google Scholar
  6. Köhler, H.-J.; Feddersen, I.; Schwab, R., 1999. Soil and structure deformations due to reconstruction of an old lock built on unsaturated submerged clay. In: Proceedings of the 2nd International Symposium on Pre-failure Deformation Characteristics of Geomaterials (ISBN 9058090752), Torino, Italy, 26th–30th September 1999, M. Jamiolkowski et al.(eds) A.A. Balkema, Rotterdam, (793–800).Google Scholar
  7. Köhler, H.-J., R. Schulze & K. Asami, 2002. Protection measures in order to increase safety of unstable clay slopes by unconventional pore pressure release techniques. In: Proceedings of the 1st European Conference on Landslides (ECL 2002), 24th–26th June 2002, Prag, Czech Republic, R. Rybar & J. Stemberk (eds.), (ISBN 90 5809 393 X) Swets & Zeitlinger Publ., P.O. Box 825, 2160 SZ Lisse, The Netherlands, (597–601).Google Scholar
  8. Köhler, H.-J., 2003. Transient excess pore water pressures causing soil deformation and hydraulic failure. In: Proceedings of the XIIIth European Conference on Soil Mechanics and Gotechnical Engineering, 25th–28th August 2003, Prag, Czech Republic, I. Vanícek (eds.), Swets & Zeitlinger Publ., P.O. Box 825, 2160 SZ Lisse, The Netherlands, Vol. 1, (415–422).Google Scholar
  9. Montenegro H., Köhler, H.-J., Holfelder, T. 2003. Inspection of excess pressure propagation in the zone of gas entrapments below the capillary fringe. In: Proceedings of the International Conference: From Experimental Evidences Towards Numerical Modelling of Unsaturated Soils, September 18th–19th, Weimar, Germany, T. Schanz (ed.), Springer, Berlin (in print).Google Scholar
  10. Montenegro H., 1995. Parameterbestimmung und Modellierung der Wasserbewegung in heterogenen Böden VDI-Verlag. VDI: Reihe 15, Umwelttechnik; Nr. 134.Google Scholar
  11. Pruess, K., C. Oldenburg and G. Moridis,, 1999. TOUGH2 User’s Guide, Version 2.0, Lawrence Berkeley National Laboratory Report LBNL-43134, Berkeley, CA.Google Scholar
  12. Schulze, R. & Köhler, 1999. Landslides in over-consolidated clay — geotechnical measurements and calculation. In: Proceedings of the XIIth European Conference on Soil Mechanics and Geotechnical Engineering, (ISBN 9058090477), Amsterdam, The Netherlands, 7th–10th June 1999; F.B.J. Barends et al.(eds) 1999, A.A. Balkema, Rotterdam, (601–608).Google Scholar
  13. Simunek, J., and M. Th. van Genuchten, 1999. Using the HYDRUS-1D and HYDRUS-2D codes for estimating unsaturated soil hydraulic and solute transport parameters, in van Genuchten, M. Th., F. J. Leij, and L. Wu (eds.) Characterization and Measurement of the Hydraulic Properties of Unsaturated Porous Media, University of California, Riverside, CA, (1523–1536).Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Hans-Jürgen Köhler
    • 1
  • Hector Montenegro
    • 1
  1. 1.Federal Waterways Engineering and Research Institute (BAW)KarlsruheGermany

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