EFFECT OF FRICTIONLESS CAPS AND BASES IN THE CYCLIC TRIAXIAL TEST

The study described herein continues with a detailed investigation of the effect of frictionless ends versus regular ends in the cyclic triaxial testing of various soils. The study involved performing some additional 130 cyclic triaxial tests on samples of the following soils, using both regular and frictionless ends: Monterey No. 0 sand, Sacramento River sand, L.A. Harbor sand, and undisturbed and remolded Champlain clay. These tests were performed under different conditions of density, anisotropic consolidation stress ratio, and cyclic frequency. In order to assure that the vasicous grease used to lubricate the ends was in fact acting as a lubricant, the cyclic tests had to be performed much slower than commonly done for earthquake studies. Therefore, the question of the effect of cyclic frequency on the indicated cyclic strength of the soil also had to be considered. For this purpose, tests were performed on samples with regular and with frictionless ends at cyclic frequencies of 1.0 Hz and 0.05 Hz. From the results of these tests, it was observed that the frequency at which the tests were run did not affect the cyclic strength of the soils tested. Thus, after establishing that the prongs and the frequency did not influence the cyclic strength of these soils, comparative tests were run to determine the effect of end restraint. The results of the end restraint studies showed that for relatively clean sands there was an increase of 10 to 30 percent in cylic strength by using frictionless ends rather than regular ends. The silty sands and clays tested were not influenced by the type of end restraint. Furthermore, the data showed a recognizable relation of an increasing strengthening influence of frictionless ends with an increasing tendency for dilation. /Author/

  • Corporate Authors:

    University of California, Los Angeles

    Department of Mechanics and Structures
    Los Angeles, CA  USA  90024
  • Authors:
    • Vernese, F J
    • Lee, K L
  • Publication Date: 1977-6

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 112 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00159604
  • Record Type: Publication
  • Report/Paper Numbers: Final Rpt.
  • Contract Numbers: DACW-39-75-M-4712
  • Files: TRIS, ATRI
  • Created Date: Nov 23 1977 12:00AM