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Application of Plasticity Theory to Soil Behavior: A New Sand Model


Bardet, Jean-Pierre (1984) Application of Plasticity Theory to Soil Behavior: A New Sand Model. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z23J-9E80.


The representation of rheological soil behavior by constitutive equations is a new branch of soil mechanics which has been expanding for 30 years. Based on continuum mechanics, numerical methods (finite elements) and experimental techniques, this new discipline allows practicing engineers to solve complex geotechnical problems. Although all soils are constituted of discrete mineral particles, forces and displacements within them are represented by continuous stresses and strains. Most stress-strain relationships, which describe the soil behavior, are derived from plasticity theory. Originated for metals, the conventional plasticity is presented and illustrated simultaneously with a metal and a soil model. Each plasticity concept may be criticized when applied to soil. A recent theory, called "bounding surface plasticity," generalizes the conventional plasticity and describes more accurately the cyclic responses of metals and clays. This new theory is first presented and linked with the conventional plasticity, then applied to a new material, sand. Step by step a new sand model is constructed, mainly from data analysis with an interactive computer code. In its present development, only monotonic loadings are investigated. In order to verify the model ability to describe sand responses, isotropic, drained and undrained tests on the dense Sacramento River sand are simulated numerically and compared with real test results and predictions with another model. Finally the new constitutive equation, which was formulated in the p-q space for axisymmetric loadings, is generalized in the six-dimensional stress state with the assumption of isotropy and a particular Lode's angle contribution. This new model is ready to be used in finite element codes to represent a sand behavior.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Civil Engineering
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Civil Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Scott, Ronald F.
Thesis Committee:
  • Iwan, Wilfred D. (chair)
  • Knowles, James K.
  • Beck, James L.
  • Scott, Ronald F.
  • Hughes, Edward Wesley
Defense Date:27 September 1983
Record Number:CaltechETD:etd-12212005-143343
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5102
Deposited By: Imported from ETD-db
Deposited On:22 Dec 2005
Last Modified:13 Jul 2023 19:15

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PDF (Bardet_jp_1984.pdf) - Final Version
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