STP599: A Technique for the Preparation of Specimens of Loose Layered Silts

    Nacci, VA
    Professor of civil and ocean engineering, University of Rhode Island, Kingston, R.I.

    D'Andrea, RA
    Assistant professor of Civil Engineering, Worcester Polytechnic Institute, Worcester, Mass.

    Pages: 9    Published: Jan 1976


    Abstract

    A brief review of previously published results of shear strength testing of silty soils is presented. It is noted that, due to their highly porous structure and the resultant unfavorable effects derived from sampling, natural silts are among the least studied deposits in the world. When found in glaciated regions, these deposits are often laminated, usually contain small amounts of clay, and, when laminated, are invariably anisotropic.

    A typical naturally occurring silt, prevalent in the area of Providence, Rhode Island, is described in terms of its geologic origin and its in situ index properties.

    An experimental procedure which entails laboratory sedimentation, consolidation under small load increments, and laboratory freezing to obtain a soil specimen which may be handled without densification, is described. It is shown that these laboratory produced specimens duplicated the in situ varved structure and index properties of the natural silt. Although the paper reports in detail on the production of cylindrical triaxial specimens, the method may be readily adapted to produce specimens of virtually any size or shape.

    In conclusion, it is pointed up that, in utilizing this technique, specimens may be prepared with virtually any angular relationship between the inclination of the layers and the directions of the applied principal stresses, facilitating the investigation of anisotropic strength effects.

    Keywords:

    soils, silts, sedimentation, freezing, anisotropy, shear strength, triaxial tests


    Paper ID: STP39083S

    Committee/Subcommittee: D18.09

    DOI: 10.1520/STP39083S


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