Abstract
The mechanical behaviour of unsaturated expansive soils is an important factor in the design of barriers for nuclear waste disposal. Double structural constitutive models for expansive soil have been developed based on the distinction between micro-structure and macro-structure of the expansive soil. Nevertheless, the micro-parameters and the coupling function of these models are hard to determine. To eliminate the limitations of these models, the concept of a macro-structural neutral loading line was introduced by adopting a simple assumption concerning the plastic swelling potential of unsaturated expansive soil. A macro-structural volume change equation of unsaturated expansive soil was derived using a macro-structural neutral loading line. The model was based on an existing model for non-expansive unsaturated soils. Only one new macro-parameter was introduced into the constitutive model compared to the original model. Finally, a comparison between predicted results and experimental data indicates that the proposed model has a remarkable ability to reproduce the mechanical and hydraulic responses of unsaturated expansive soils.
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References
Alonso EE, Gens A, Josa A (1990) A constitutive model for partially saturated soils. Géotechnique 40(3):405–430
Alonso E, Vaunat J, Gens A (1999) Modelling the mechanical behaviour of expansive clays. Eng Geol 54(1):173–183
Blight G (1965) The time-rate of heave of structures on expansive clay. In: Aithison GD (ed), Moisture equilibria and moisture changes in soils beneath covered areas. Butterworths, Syndey, pp 78–88
Chapman DL (1913) LI. A contribution to the theory of electrocapillarity. Phil Mag 25(148):475–481
Chiu CF, Ng CWW (2003) A state dependent elasto-plastic model for saturated and unsaturated soils. Géotechnique 53(9):809–929
Cui Y, Delage P (1996) Yielding and plastic behaviour of an unsaturated compacted silt. Géotechnique 46(2):291–311
Delage P, Graham J (1995) Understanding the behaviour of unsaturated soils requires reliable conceptual models: state of the art report. In: Alonso EE, Delage P (eds) Proceedings of the first international conference on unsaturated soils. UNSAT '95, Paris, France, pp 1223–1256
Fredlund DG, Xing A (1994) Equations for the soil–water characteristic curve. Can Geotech J 31(4):521–532
Gens A, Alonso E (1992) A framework for the behaviour of unsaturated expansive clays. Can Geotech J 29(6):1013–1032
Georgiadis K, Potts DM, Zdravkovic L (2005) Three dimensional constitutive model for partially and fully saturated soils. Int J Geomech 5(3):244–255
Gouy G (1910) Sur la constitution de la charge electrique a la surface d’un electrolyte. Physique 9(1):457–468
Gouy G (1917) Sur la fonction électrocapillaire. Annales de Physique 7(9):129–184
Graham J, Oswell JM, Gray MN (1992) The effective stress concept in saturated sand-clay buffer. Can Geotech J 29:1033–1043
Kassiff G, Shalom AB (1971) Experimental relationship between swell pressure and suction. Géotechnique 21(3):245–255
Lloret A, Villar MV, Sanchez M, Gens A, Pintado X, Alonso E (2003) Mechanical behaviour of heavily compacted bentonite under high suction changes. Géotechnique 53(1):27–40
Masin D (2010) Predicting the dependency of a degree of saturation on void ratio and suction using effective stress principle for unsaturated soils. Int J Numer Anal Methods Geomech 34:73–90
Mualem Y (1976) A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resour Res 12(3):513–522
Roscoe KH, Burland J (1968) On the generalized stress-strain behaviour of wet clay. In: Heyman J, Leckie FA (eds) Engineering plasticity. Cambridge University Press, Cambridge, pp 535–609
Sheng D (2011) Review of fundamental principles in modelling unsaturated soil behaviour. Comput Geotech 38(6):757–776
Sheng D, Zhou AN (2011) Coupling hydraulic with mechanical models for unsaturated soils. Can Geotech J 48(5):826–840
Sheng D, Fredlund DG, Gens A (2008) A new modelling approach for unsaturated soils using independent stress variables. Can Geotech J 45(4):511–534
Sun DA, Sheng D, Cui H, Sloan S (2007) A density-dependent elastoplastic hydro-mechanical model for unsaturated compacted soils. Int J Numer Anal Methods Geomech 31(11):1257–1279
Sun DA, Sun WJ, Yan W (2009) Hydraulic and mechanical behaviour of sand-bentonite mixture. Proceedings of the international symposium on unsaturated soil mechanics and deep geological nuclear waste disposal, Shanghai, 90–97
Thu TM, Rahardjo H, Leong EH (2007) Elastroplastic model for unsaturated soil with incorporation of the soil–water characteristic curve. Can Geotech J 44(1):67–77
Van Genuchten MT (1980) A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44(5):892–898
Wheeler SJ, Sivakumar V (1995) An elasto-plastic critical state framework for unsaturated soil. Géotechnique 45(1):35–53
Yong R, Sadana M, Gohl W (1984) A particle interaction energy model for assessment of swelling of an expansive soil. Proceedings of the 5th international conference on expansive soils. Adelaide, Australia, pp 4–12
Zhan L (2003) Field and laboratory study of an unsaturated expansive soil associated with rain-induced slope instability. PhD thesis. The Hong Kong University of Science and Technology, Hong Kong
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The authors appreciate the financial support of the National Science Foundation of China, No. 41572252.
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Li, W., Yang, Q. A macro-structural constitutive model for partially saturated expansive soils. Bull Eng Geol Environ 76, 1075–1084 (2017). https://doi.org/10.1007/s10064-016-0933-z
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DOI: https://doi.org/10.1007/s10064-016-0933-z