Spatial Deformation Measurement Using Transparent Soil

    Volume 33, Issue 4 (July 2010)

    ISSN: 0149-6115

    CODEN: GTJOAD

    Published Online: 15 June 2010

    Page Count: 8


    Iskander, Magued
    Associate Professor, Polytechnic Institute of New York Univ., Brooklyn, NY

    Liu, Jinyuan
    Assistant Professor, Ryerson Univ., Toronto, ON

    (Received 19 September 2009; accepted 1 April 2010)

    Abstract

    This paper addresses the need for nonintrusively measuring spatial deformation pattern inside soils. In this study, transparent soil surrogates are used in model tests instead of natural soils. Transparent soil with macrogeotechnical properties similar to those of natural soils was made of either transparent amorphous silica gels or powders and a pore fluid with a matching refractive index. An optical system consisting of a laser light, a line-generator lens, a charge-coupled device (CCD) camera, a frame grabber, and a computer was developed to optically slice a transparent soil model. A distinctive speckle pattern is generated by the interaction of the laser light and transparent soil. The laser speckle images before and after deformation were used to nonintrusively measure the relative displacement field using digital image cross-correlation. Spatial displacement fields under a model footing were obtained by combining several cross-sections in MATLAB®. Test results showed that the developed optical system and transparent soil are suitable for studying soil-structural interaction problems.


    Paper ID: GTJ102745

    DOI: 10.1520/GTJ102745

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    Author
    Title Spatial Deformation Measurement Using Transparent Soil
    Symposium , 0000-00-00
    Committee D18