SMALL STRAIN STIFFNESS OF NATURAL GRANITIC SAPROLITE IN HONG KONG

Nonlinear stress-strain characteristics and shear stiffness-shear strain relationships of sedimentary soils and recompacted sands at small strains have been reported by many researchers. However, research work on the behavior of granitic soils at small strains has not attracted much attention, despite the fact that many countries around the world are underlain by granitic saprolites. In this study, shear stiffness of a natural granitic saprolite from Hong Kong was investigated in the field, using the self-boring pressuremeter and geophysical techniques such as the suspension P-wave and S-wave logging method, and in the laboratory, using a triaxial apparatus equipped with internal displacement measuring devices. The observed stiffness-strain relationships of the natural granitic saprolite were highly nonlinear at small strains. Shear stiffness decreased significantly as shear strain increased. At very small shear strains (in the order of 0.001%), the elastic shear moduli deduced from the suspension S-wave logging method were generally consistent with the predictions made using an empirical correlation based on standard penetration test N values and also with the results of triaxial tests incorporating local displacement measurements. For shear strains larger than 0.01%, reasonable consistency was found between the normalized shear stiffness-shear strain relationships obtained using the self-boring pressuremeter and from the triaxial apparatus.

  • Availability:
  • Supplemental Notes:
    • Funding for this research was provided by the Research Grants Council of Hong Kong with research grant CRC96/99.EG04.
  • Corporate Authors:

    American Society of Civil Engineers

    1801 Alexander Bell Drive
    Reston, VA  United States  20191-4400
  • Authors:
    • Ng, CWW
    • Pun, W K
    • Pang, RPL
  • Publication Date: 2000-9

Language

  • English

Media Info

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Filing Info

  • Accession Number: 00798453
  • Record Type: Publication
  • Contract Numbers: CRC96/99.EG04, CMS 9115316, CES 8711764
  • Files: TRIS
  • Created Date: Sep 18 2000 12:00AM