CREEP STUDIES ON SATURATED CLAYS WITH DISCUSSION

An hypothesis, based on rate-process theory, which relates effective stresses, deviator stress, soil structure, temperature, and frictional and cohesive soil properties with creep rate, is summarized briefly. This hypothesis is tested by a specially designed triaxial compression apparatus which permits creep testing of clays under a range of controllable temperatures and pressures as well as the measurement of pore water pressures. This apparatus alos permits rapid temperature change during a test. Data are presented to show that effective stresses and creep behavior of saturated clays are very sensitive to temperature variations when the clay is tested under undrained conditions. A temperature increase leads to a significant decrease in effective stresses and an increase in strain rate for creep under both a constant sustained deviator stress and a constant sustained effective principal stress ratio. For conditions of constant temperature, soil structure, and effective stresses, the logarithm of the creep rate varies linearly with deviator stress according to predictions of the hypothesis. Discussion: D.J. Henkel and V.A. Sowa state that for the study of creep phenomena, a constant temperature environment is essential. In addition, the effect of cyclic temperature changes on the pore water pressure of an undrained soil specimen (Weald clay) were examined, the authors found that: (1) the pore water pressure change for fluctuating temperature does not form a closed hysteresis loop, but a genuine increase occurs; (2) the grandual increase in pore water pressure is the result of the procedure and the particular apparatus used. Robert L. Kondner suggests the authors present their creep data in the form of creep compliance as a function of time.

  • Corporate Authors:

    American Society for Testing and Materials

    100 Barr Harbor Drive, P.O. Box C700
    West Conshohocken, PA  United States  19428-2957
  • Authors:
    • Mitchell, J K
    • Campanella, R G
  • Discussers:
    • Henkel, D J
    • Sowa, V A
  • Publication Date: 1963-9

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Filing Info

  • Accession Number: 00095095
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 7 1975 12:00AM