Why the OCR may reduce the small strain shear stiffness of granular materials?
- 281 Downloads
The small strain shear stiffness G0 of the soil is of interest and importance in both theory and practice. It is expected that for granular materials G0 would slightly increases with over-consolidation ratio (OCR). However, laboratory tests indicate that G0 may decrease with increasing OCR, especially for loose specimens, which is counterintuitive. To explore the underlying mechanism, discrete element method (DEM) is used to investigate the effect of OCR on G0. The DEM simulations successfully capture the laboratory observations. The analyses at the particulate level reveal that the decrease in small strain stiffness is mainly due to the decreases in coordination number and the uniformity of contact force distribution during unloading process.
KeywordsDiscrete element method Micromechanics OCR Poisson’s ratio Small strain stiffness
The work presented in this paper is supported by National Key Research and Development Program (Grant No. 2016YFC0800200), National Natural Science Foundation of China (Grant Nos. 51308408, 41772283) and Fundamental Research Funds for the Central Universities. These supports are gratefully acknowledged.
- 4.Gu X (2012) Dynamic properties of granular materials at the macro and micro scales. Dissertation, The University of Hong KongGoogle Scholar
- 10.Hardin BO (1978) The nature of stress–strain behavior for soils. In: Proceeding of specialty conference on earthquake engineering and soil dynamics. ASCE, Pasadena, pp 3–90Google Scholar
- 11.Hardin BO, Richart FE (1963) Elastic wave velocities in granular soils. J Soil Mech Found Div ASCE 89(SM1):39–56Google Scholar
- 14.Itasca (2009) Particle flow code (PFC3D) manual. Itasca Consulting Group Inc, MinneapolisGoogle Scholar
- 15.Kiyota T, De Silva LIN, Sato T, Koseki J (2006) Small strain deformation characteristics of granular materials in torsional shear and triaxial tests with local deformation measurements. In: Hoe I et al (eds) Soil stress–strain behavior: measurement, modeling and analysis: a collection of papers of the geotechnical symposium in Rome Ling. Springer, Dordrecht, pp 557–566Google Scholar
- 21.Tatsuoka F, Shibuya S, Teachavorasinskun S (1991) Discussion on “Shear modulus and cyclic undrained behavior of sands”. Soils Found 31(2):202–209Google Scholar