Coupled effects of suction and degree of saturation on large strain shear modulus of unsaturated sands

Jafarzadeh, F ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1201/b17034-228
  3. Abstract:
  4. Predictions of soil behavior in response to dynamic loads require an understanding of dynamic properties of soil. Studies on dynamic properties of unsaturated soils at large-strains are quite limited, while some dynamic loadings, like earthquakes, are in the medium to large-strain ranges. A cyclic simple shear apparatus was developed to measure large-strain shear modulus and damping ratio under different matric suction or degree of saturation. Six cyclic tests, with referring to the soil-water retention curve, were conducted on clean medium sand. Results indicated that shear modulus slightly increases when suction varies from zero up to the air entry value. Approaching the residual value, a significant increase in shear modulus was observed. Dynamic stiffness is approximately constant beyond residual point. The importance of particles lubrication was demonstrated by comparing experimental results with predicted values from literature. A model was proposed for particles lubrication function and calibrated and verified for tests conditions in this study
  5. Keywords:
  6. Dynamic loads ; Elastic moduli ; Lubrication ; Shear strain ; Supersaturation ; Cyclic simple shear ; Degree of saturations ; Dynamic loadings ; Dynamic property ; Dynamic stiffness ; Soil water retention ; Unsaturated sand ; Unsaturated soil ; Soils
  7. Source: Unsaturated Soils: Research and Applications - Proceedings of the 6th International Conference on Unsaturated Soils, UNSAT 2014 ; Vol. 2, issue , July , 2014 , p. 1559-1564 ; 978-1-138-00150-3
  8. URL: http://www.crcnetbase.com/doi/abs/10.1201/b17034-228