Effect of Strain-Softening in Interpretation of Laboratory Compression Tests

  • L. Andresen
  • H. P. Jostad
Conference paper
Part of the International Centre for Mechanical Sciences book series (CISM, volume 397)


The interpretation of post-peak stress-strain relationship from laboratory compression tests performed on strain-softening clay specimens under undrained condition is considered. Since failure of a strain-softening material is accompanied by strain localization, the post-peak stress and strain distributions will be highly inhomogeneous. Standard interpretation techniques will then overestimate the rate of softening significantly, i.e. the steepness of the post-peak stress-strain curve is overestimated. Finite element analyses of a biaxial compression test are used to demonstrate this effect by simulation. The effect of strain-softening is accounted for by an elasto-plastic strain softening material model within the concept of total stresses, using the Tresca yield criterion. Some comments are also made concerning the severe mesh dependency associated with the use of a strain-softening material model.


Peak Strength Biaxial Test Plane Strain Compression Peak Shear Strength Plastic Shear Strain 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. BRINKGREVE, R.B.J. (1994). Geomaterial models and numerical analysis of softening Ph.d. thesis, Delft University of Technology.Google Scholar
  2. CRISFIELD, M.A. (1982). Accelerated solution techniques and concrete cracking. Comp. Meth. in Appl. Mech. and Eng., 33, 585–607CrossRefMATHGoogle Scholar
  3. JOSTAD, H.P. (1993). Bifurcation analysis of frictional materials. Ph.d. thesis, University of Trondheim, Norwegian Institute of TechnologyGoogle Scholar
  4. LACASSE S., T. BERRE & G. LEFEBVRE (1985). Block Sampling of Sensitive Clays. XI Int. Conf. on Soil Mech. and Found. Eng., San Francisco, Vol. 2: 887–892Google Scholar
  5. LADD, C.C. (1971). Strength Parameters and Stress-Strain Behaviour of Saturated Clays. MIT, Dep. of Civil Eng., Research Report R71–23Google Scholar
  6. LIZCANO A., I. VARDOULAKIS & M. GOLDSCHEIDER (1997). Biaxial tests on normally, anisotropically consolidated clay. Proc. Def. and Prog. Failure in Geomech., IS NAGOYA’97: 223–228Google Scholar
  7. PIETRUSZCZAK, ST. & D.E.F. STOLLE (1985). Part I: Objectivity of finite element solutions based on conventional strain softening formulations. Computers and Geotechnic 1, 99–115CrossRefGoogle Scholar
  8. PIETRUSZCZAK, S.T. & Z. MRÓZ (1981). Finite Element Analysis of Deformation of Strain-Softening Materials. Int. J. Num. Meth. Eng., Vol. 17, 327–334, 1981CrossRefMATHGoogle Scholar
  9. RHEE, Y. (1991). Experimental evaluation of strain-softening behaviour of normally consolidated Chicago clays in plane strain compression. Ph.D. thesis, Northwestern University, IL, USA, 1991Google Scholar
  10. VERMEER, P.A. & R. DE BORST (1984) Non-associated plasticity for soil, concrete and rock. HERON 29, NO. 3, pp. 1–64.Google Scholar

Copyright information

© Springer-Verlag Wien 1998

Authors and Affiliations

  • L. Andresen
    • 1
  • H. P. Jostad
    • 1
  1. 1.Norwegian Geotechnical InstituteOsloNorway

Personalised recommendations