Constitutive modelling of shear stiffness degradation at various suctions and temperatures

Chao Zhou, Charles Wang Wai Ng

Research output: Unpublished conference presentation (presented paper, abstract, poster)Conference presentation (not published in journal/proceeding/book)Academic researchpeer-review

2 Citations (Scopus)


Some thermo-mechanical models have been reported for unsaturated soils. None of them is developed purposely to capture the nonlinearity of stress-strain curves and stiffness degradation at small strains (less than 1%). These existing models cannot therefore accurately predict ground movements and the performance of many civil structures under working conditions. In this paper, a new thermo-mechanical model is developed by using the bounding surface plasticity theory. Different from conventional elastoplastic models, plastic strain is allowed inside the bounding surface for capturing the degradation of soil stiffness with strain. This model is developed in terms of mean Bishop's stress, deviator stress, suction, temperature, specific volume and degree of saturation. Thermal, hydraulic and mechanical behaviour of soil are fully coupled. To evaluate capability of the model, it is applied to simulate suction and temperature controlled triaxial shear tests on a compacted silt. It is evident that computed stress-strain relations and stiffness degradation curves are generally consistent with measured responses at various suctions and temperatures.

Original languageEnglish
Number of pages4
Publication statusPublished - 1 Jan 2017
Externally publishedYes
Event19th International Conference on Soil Mechanics and Geotechnical Engineering, ICSMGE 2017 - Coex Convention Center, Seoul, Korea, Republic of
Duration: 17 Sep 201722 Sep 2017


Conference19th International Conference on Soil Mechanics and Geotechnical Engineering, ICSMGE 2017
Country/TerritoryKorea, Republic of


  • Constitutive model
  • Non-linearity
  • Small stain
  • Thermal effects
  • Unsaturated soil

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology

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