Volume 17, Issue 4 (December 1994)

    Time-Dependent Triaxial Relaxation Behavior of a Resedimented Clay

    CODEN: GTJOAD

      Format Pages Price  
    PDF Version 9 $25   ADD TO CART


    Abstract

    The paper describes the results of K0 consolidated-undrained triaxial compression relaxation tests on resedimented Boston Blue Clay (BBC) using a computer-automated triaxial apparatus. Specimens were either normally consolidated (overconsolidation ratio, OCR = 1) or had an OCR = 4, and they were sheared at different axial strain rates to axial strains (εa) from 0.1 to 15%. Each strain level was maintained until the monitored shear stress and pore pressure reached equilibrium levels. The results show that a single specimen can be used reliably for multiple relaxation tests. During relaxation, the rate of normalized shear stress decay with log time, (−Δq/σ′vm)/Δlogt, is approximately constant, regardless of εa or OCR. Changes in shear-induced pore pressure during relaxation were negligible except when specimens were rapidly sheared. Independent of OCR, end-of-relaxation equilibrium stress states for relaxation strains εa ≤ 1.5% lie on a line of obliquity defined by K = σ′h/σ′v = 0.50, compared to K0 = 0.49 for OCR = 1 BBC; whereas, for εa ≥ 2.5%, the equilibrium states lie on a steeper obliquity line defined by K = 0.40.


    Author Information:

    Sheahan, TC
    Assistant professor, Northeastern University, Boston, MA

    Ladd, CC
    Professor, Massachusetts Institute of Technology, Cambridge, MA

    Germaine, JT
    Principal research associate, Massachusetts Institute of Technology, Cambridge, MA


    Stock #: GTJ10305J

    ISSN: 0149-6115

    DOI: 10.1520/GTJ10305J

    ASTM International is a member of CrossRef.

    Author
    Title Time-Dependent Triaxial Relaxation Behavior of a Resedimented Clay
    Symposium , 0000-00-00
    Committee D18