STP599: Effect of Specimen Preparation Method on Grain Arrangement and Compressibility in Sand

    Mahmood, A
    Project engineer, Woodward-Clyde Consultants, Orange, Calif.

    Mitchell, JK
    Professor of civil engineering, University of California, Berkeley, Calif.

    Lindblom, U
    Head, Hagconsult, Stockholm, Sweden

    Pages: 24    Published: Jan 1976


    Abstract

    Effects of methods of specimen preparation on fabric and compressibility were investigated in a medium grain-sized sand. The effect of vibratory compaction was compared with the effect of pluviation by characterizing the particle arrangements and measuring compressibility in a specially fabricated oedometer. The lateral stresses during compression were also measured.

    Specimens densified by vibration in layers had random grain orientation up to 100 percent relative density. When vibration was continued beyond the time interval needed for achieving 100 percent relative density, the grains acquired a preferred orientation. Pluviated specimens had randomly oriented grains at both low and high densities.

    The loose, pluviated specimens were much more compressible than the dense specimens prepared by the same procedure. The dense specimens when prepared by vibration were less compressible than the pluviated specimens. The lateral stresses were higher in the loose pluviated specimens than in the dense pluviated specimens during loading. On unloading, the same trend was present initially but reversed at lower axial loads. This trend was also measured in the specimens prepared by vibration.

    Keywords:

    sands, soils, tests, specimen preparation, fabric, compressibility, vibration, laboratory studies, oedometers


    Paper ID: STP39082S

    Committee/Subcommittee: D18.09

    DOI: 10.1520/STP39082S


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