New Search

Export article

On the fundamental nature of the state parameter

Michael Jefferies
Published: 12 November 2021

Abstract: The state parameter ψ is widely used for soil characterisation and as a controlling parameter in modern constitutive understanding of soil, but there remains a perception that the control of soil strength by ψ is merely that of a correlation. This perception possibly stems from ψ having been introduced from ‘principles’ of critical state theory rather than derived, which is now rectified. It is shown that the control of limiting dilatancy by the state parameter (and thus soil strength through stress–dilatancy) is a formal mathematical consequence of Casagrande's canonical characterisation linking void ratio to soil constitutive behaviour. This formal consequence is independent of soil type, being applicable across the spectrum from clays to sands. Three dimensionless and familiar soil properties are involved in addition to those characterising the critical state locus: Mtc, N and X. The framework is kinematic, with no constitutive model: it is a constraint on models. Example data are shown for sands, silts and clays to illustrate the independence of the theory from geological descriptors.
Keywords: constitutive / characterisation / state parameter / stress / soil / dilatancy / formal / models / clays

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

Share this article

Click here to see the statistics on "Géotechnique" .
References (33)
    Back to Top Top