Advertisement

A Double Cell Triaxial Apparatus for Testing Unsaturated Soil Under Heating and Cooling

  • Qing ChengEmail author
  • Raejee Kaewsong
  • Chao Zhou
  • Charles Wang Wai Ng
Conference paper
Part of the Springer Series in Geomechanics and Geoengineering book series (SSGG)

Abstract

To study thermo-hydro-mechanical behaviour of unsaturated soil, some apparatuses are developed and reported in the literature. Most of the existing apparatuses, however, cannot apply cooling and control temperature lower than room temperature. Moreover, an accurate measurement of thermal volume changes is still challenging, particularly for unsaturated soil. In this study, a triaxial apparatus with double cell total volume change measuring system is modified to fulfil temperature control in a wide temperature range (both higher and lower than room temperature). Temperature is regulated by circulating water with a controlled temperature in a spiral copper tube installed between the inner and outer cells. Detailed calibrations are carried out to determine the response of heating/cooling system and double cell to heating and cooling, such as the thermal equilibrium time and the volume change of inner cell. By using the new apparatus, a series of test is carried out to investigate the volume changes of normally consolidated intact and recompacted loess at different suctions over a wide thermal cycle ranging from 5 °C to 53 °C. It is found that contractive volumetric strain increases as temperature increases. During the cooling process, soil volume keeps contracting until the temperature decreases to 5 °C. An irreversible contraction at a much higher rate is observed from 13 °C to 5 °C. The observed plastic strain during cooling cannot be captured by existing thermo-mechanical models.

Keywords

Volumetric Strain Unsaturated Soil Soil Specimen Double Cell Initial Void Ratio 
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.

Notes

Acknowledgements

The authors would like to acknowledge the financial support provided by the National Natural Science Foundation of China through the research grant 51509041. In addition, the authors would like to thank the Research Grants Council of the Hong Kong Special Administrative Region (HKSAR) for their financial support from Projects 616812 and 16209415.

References

  1. Abuel-Naga H, Bergado DT, Bouazza A, Ramana GV (2007) Volume change behaviour of saturated clays under drained heating conditions: experimental results and constitutive modelling. Can Geotech J 44(8):942–956. doi: 10.1139/t07-031 CrossRefGoogle Scholar
  2. ASTM (2006) Standard practice for classification of soils for engineering purposes (unified soil classification system). American Society of Testing and Materials, West ConshohockenGoogle Scholar
  3. Cai GQ, Zhao CG, Li J, Liu Y (2014) A new triaxial apparatus for testing soil water retention curves of unsaturated soils under different temperatures. J Zhejiang Univ Sci A 15(5):364–373CrossRefGoogle Scholar
  4. Campanella RG, Mitchell JK (1968) Influence of temperature variations on soil behaviour. J Soil Mech Found Div 94(3):709–734. ASCEGoogle Scholar
  5. Coccia CJR, McCartney JS (2016) High-pressure thermal isotropic cell for evaluation of thermal volume change of soils. Geotech Test J 3(2):217–234. doi: 10.1520/GTJ20150114. ASTM
  6. Delage P, Sultan N, Cui YJ (2000) On the thermal consolidation of boom clay. Can Geotech J 37(2):343–354. doi: 10.1139/t99-105 CrossRefzbMATHGoogle Scholar
  7. Di Donna A, Laloui L (2015) Response of soil subjected to thermal cyclic loading: experimental and constitutive study. Eng Geol 190:65–76. doi: 10.1016/j.enggeo.2015.03.003 CrossRefGoogle Scholar
  8. Gens A (2010) Soil-environment interactions in geotechnical engineering. Géotechnique 60(1):3–74. doi: 10.1680/geot.9.P.109 CrossRefGoogle Scholar
  9. Ng CWW, Cheng Q, Zhou C, Alonso EE (2016) Volume changes of an unsaturated clay during heating and cooling. Géotechnique Lett 6(3):1–7. doi: 10.1680/jgele.16.00059 CrossRefGoogle Scholar
  10. Ng CWW, Lai CH, Chiu CF (2012) A modified triaxial apparatus for measuring the stress path-dependent water retention curve. Geotech Test J 35(3):490–495. doi: 10.1520/GTJ104203 CrossRefGoogle Scholar
  11. Ng CWW, Zhan LT, Cui YJ (2002) A new simple system for measuring volume changes in unsaturated soils. Can Geotech J 39(3):757–764. doi: 10.1139/t02-015 CrossRefGoogle Scholar
  12. Romero E, Gens A, Lloret A (2003) Suction effects on a compacted clay under non-isothermal conditions. Géotechnique 53(1):65–81. doi: 10.1680/geot.2003.53.1.65 CrossRefGoogle Scholar
  13. Uchaipichat A, Khalili N (2009) Experimental investigation of thermo-hydro-mechanical behaviour of an unsaturated silt. Géotechnique 59(4):339–353. doi: 10.1680/geot.2009.59.4.339 CrossRefGoogle Scholar
  14. Zhou C, Ng CWW (2015) A thermo-mechanical model for saturated soil at small and large strains. Can Geotech J 52(8):1101–1110. doi: 10.1139/cgj-2014-0229 CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • Qing Cheng
    • 1
    Email author
  • Raejee Kaewsong
    • 1
  • Chao Zhou
    • 1
  • Charles Wang Wai Ng
    • 1
  1. 1.Department of Civil and Environmental EngineeringHong Kong University of Science and TechnologyKowloonHong Kong

Personalised recommendations