Dynamic shear modulus and damping ratio of k0 consolidated saturated clays

WANG Jianhua1,2 YANG Teng1,2

(1.State Key Laboratory of Hydraulic Engineering Simulation and Safety of Tianjin University, Tianjin, China 300072)
(2.Geotechnical Engineering Institute of Tianjin University, Tianjin, China 300072)

【Abstract】Influences of the initial average effective stress, the initial shear stress and the dynamic stress history on the dynamic shear modulus and the damping ratio of k0 consolidated saturated clays are studied by dynamic triaxial tests. The following conclusions are obtained. The dynamic accumulative strain can be used as a state parameter to describe the influence of the dynamic stress history on the dynamic shear modulus. The influences of the initial shear stress on the dynamic shear modulus and the damping ratio can be described by expressing the dynamic shear modulus and the damping ratio as variations with the dynamic shear strain. The influence of the initial average effective stress can be considered by normalizing the relationship between the dynamic shear modulus and the dynamic shear strain by using the maximum shear modulus associated with the relationship. Because effects of the initial average effective stress, the initial shear stress and the dynamic stress history on the variation of the damping ratio with the dynamic shear strain are not obvious, it is considered that the damping ratio is only related with the dynamic shear strain. Therefore, variation relationship of the dynamic shear modulus and the damping ratio with the initial average effective stress, the initial shear stress, the dynamic stress history and the dynamic shear strain can be determined by a group of dynamic triaxial tests under a consolidation confining pressure and multi-stages dynamic triaixial test of a sample under different confining pressure.

【Keywords】 cyclic shear modulus; damping ratio; k0 consolidated clay; dynamic constitutive relationship; dynamic triaxial tests;

【DOI】

【Funds】 National Natural Science Foundation of China (51579174)

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    References

    [1] XIE Dingyi. Soil dynamics [M]. Beijing: Higher Education Press, 2011 (in Chinese).

    [2] Park D. Evaluation of dynamic soil properties: strain amplitude effects on shear modulus and damping ratio [M]. Cornell University, May, 1998.

    [3] Roesler S K. Anisotropic shear modulus due to stress anisotropy [J]. Journal of the Geotechnical Engineering Division, 1973, 105 (7): 871–880.

    [4] Kokusho T, Yoshida Y, Esashi Y. Dynamic properties of soft clay for wide strain range [J]. Soils and Foundations, 1982, 22 (4): 1–18.

    [5] Stokoe K H, Hwang S K, Lee N K, et al. Effects of various parameters on the stiffness and damping of soils at small to medium strains [C]. //International Symposium on the Pre-Failure Deformation Characteristics of Geomaterials. 1995.

    [6] Ni S H. Dynamic Properties of sand under true triaxial stress states from resonant column torsional shear tests [D]. The University of Texas at Austin, Austin, Texas, 1987.

    [7] GUO Tingting, QIN Meimei. Theoretic analysis of parameters selection of dynamic triaxial tests [J]. Earthquake Resistant Engineering and Retrofitting, 2016, 38 (2): 144–149 (in Chinese with English abstract).

    [8] HE Weimin, LI Deqing, YANG Jie, et al. Recent progress in research on dynamic shear modulus, damping ratio of soil [J]. Earthquake Resistant Engineering and Retrofitting, 2016, 38 (2): 309–317 (in Chinese with English abstract).

    [9] SUN Jing, YUAN Xiaoming. Effect of consolidation ratio of cohesive soils on dynamic shear modulus [J]. Rock and Soil Mechanics, 2010, 31 (5): 1457–1462 (in Chinese with English abstract).

    [10] CAI Yuanqiang, WANG Jun, XU Changjie. Experimental study on dynamic elastic modulus and damping ratio of Xiaoshan saturated soft clay considering initial deviator stress [J]. Rock and Soil Mechanics, 2007, 28 (11): 2291–2302 (in Chinese with English abstract).

    [11] Tatsuoka, Iwasaki, Fukushima, Sudo. Stress conditions and stress histories affecting shear modulus and damping of sand under dynamic loading [J]. Soils and Foundations, 1979, 19 (2): 29–43.

    [12] WANG Jianhua, LI Shuzhao. A pseudo-dynamic relationship for describing the dynamic stress-strain response of soft clays in undrained conditions [J]. China Earthquake Engineering Journal, 2014, 36 (3): 421–428 (in Chinese with English abstract).

    [13] Subramaniam P, Banerjee S. Shear modulus degradation model for cohesive soils [J]. Soil Dynamics and Earthquake Engineering, 2013, 53 (10): 210–216.

    [14] Zhou J, Gong X. Strain degradation of saturated clay under dynamic loading [J]. Canadian Geotechnical Journal, 2001, 38 (1): 208–212.

This Article

ISSN:1004-4574

CN: 23-1324/X

Vol 27, No. 06, Pages 1-9

December 2018

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Article Outline

Abstract

  • 1 Dynamic triaxial test
  • 2 Method for determining dynamic shear modulus and damping ratio
  • 3 Relationship between dynamic shear modulus of k0 consolidated saturated clay
  • 4 Relationship between damping ratio of k0 consolidated saturated clay
  • 5 Conclusions
  • References