A new thermo-mechanical model for structured soil

C. Zhou, Charles Wang Wai Ng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

21 Citations (Scopus)

Abstract

Although thermo-mechanical behaviour of soil is strongly affected by structure, as far as the authors are aware, none of the existing constitutive models has incorporated structure effects. Consequently, the thermo-mechanical behaviour of a soil with various structures (e.g. reconstituted, intact and recompacted specimens) cannot be captured by using a single set of parameters. In the present study, a new thermo-mechanical elastoplastic model is proposed for structured soil. The model is appropriate for predicting soil behaviour under one-dimensional and triaxial stress conditions. It is assumed that soil structure affects thermo-plasticity through three different mechanisms: (a) structured soil (e.g. intact and recompacted specimens) has a larger preconsolidation pressure than the corresponding reconstituted soil at a given temperature, stress and density condition; (b) thermal softening (i.e. the reduction of preconsolidation pressure with increasing temperature) of structured soil is smaller than that of reconstituted soil; (c) degradation of soil structure contributes to plastic thermal strain. To verify the new model, it is applied to simulate the behaviour of reconstituted, intact and recompacted loess (low-plasticity clay) under cyclic heating and cooling. Experimental results and model predictions are well matched. It is evident that, with a single set of parameters, the proposed model is able to capture cyclic thermal behaviour of a soil with various structures.

Original languageEnglish
Pages (from-to)1109-1115
Number of pages7
JournalGeotechnique
Volume68
Issue number12
DOIs
Publication statusPublished - 1 Dec 2018
Externally publishedYes

Keywords

  • Constitutive relations
  • Temperature effects

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology
  • Earth and Planetary Sciences (miscellaneous)

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