The effect of the degree of saturation on the cyclic response of compacted specimens of Monterey No. 20-30 sand was investigated using cyclic triaxial test methods. Standard stress controlled cyclic triaxial tests were conducted on specimens exhibiting a high degree of saturation, and cyclic triaxial tests with pulsating axial and lateral pressures were performed on samples at lower degrees of saturation. Specimens were tested at two relative densities and at varying degrees of saturation. Test results indicate that degrees of saturation in excess of 99.0% for both loosely and densely compacted specimens must be achieved before liquefaction occurs in less than 1000 cycles of loading for any stress ratio studied. Typical results which define pore pressure response and double amplitude axial strain versus the logarithm of the number of cycles of load application for various stress ratios, are presented. These results show that the number of cycles to achieve a specified strain at a constant cyclic stress ratio increase with decreasing B values. A linear relationship was observed for both loose and dense specimens when B values were plotted as a function of the logarithm of the number of cycles of load application to achieve 5 percent double amplitude strain for both loose and dense samples. Results also indicate that low B-values had a greater affect on the cyclic strength of soils under a low cyclic stress ratio than under a high cyclic stress ratio for both loose and densely compacted sands. Results from this study are shown to agree qualitatively with data previously presented by Rocker (1968). In addition, results are also explained in a qualitative manner by the liquefaction concepts developed by Martin, et. al. (1975). /Author/

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 342-358

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Filing Info

  • Accession Number: 00179754
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Oct 12 1978 12:00AM