A Framework Interpreting Bender Element Tests, Combining Time-Domain and Frequency-Domain Methods

    Volume 32, Issue 2 (March 2009)

    ISSN: 0149-6115

    CODEN: GTJOAD

    Published Online: 1 December 2008

    Page Count: 17


    Viana da Fonseca, António
    Associate Professor, Universidade do Porto, Faculdade Engenharia, DECivil, Porto,

    Ferreira, Cristiana
    Senior Research Assistant, Universidade do Porto, Faculdade Engenharia, DECivil, Porto,

    Fahey, Martin
    Professor, School of Civil & Resource Engineering, The University of Western Australia, Crawley, WA

    (Received 9 January 2007; accepted 22 October 2008)

    Abstract

    Bender element (BE) testing is a powerful and increasingly common laboratory technique for determining the shear S-wave velocity of geomaterials. There are several advantages of BE testing, but there is no standard developed for the testing procedures or for the interpretation of the results. This leads to high degree of uncertainty and subjectivity in the interpretation. In this paper, the authors review the most common methods for the interpretation of BE tests, discuss some important technical requirements to minimize errors, and propose a practical framework for BE testing, based on the comparison of different interpretation techniques in order to obtain the most reliable value for the travel time. This new procedure consists of the application of a methodical, systematic, and objective approach for the interpretation of the results, in the time and frequency domains. The use of an automated tool enables unbiased information to be obtained regarding variations in the results to assist in the decision of the travel time. Two natural soils were tested: residual soil from Porto granite, and Toyoura sand. Specimens were subjected to the same isotropic stress conditions and the results obtained provided insights on the effects of soil type and confining stress on the interpretation of BE results; namely, the differences in testing dry versus saturated soils, and in testing uniform versus well-graded soils.


    Paper ID: GTJ100974

    DOI: 10.1520/GTJ100974

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    Title A Framework Interpreting Bender Element Tests, Combining Time-Domain and Frequency-Domain Methods
    Symposium , 0000-00-00
    Committee D18