Investigation of Resonant Frequency and Amplitude of Vibrating Footing Resting on a Layered Soil System

    Volume 24, Issue 4 (December 2001)

    ISSN: 0149-6115

    CODEN: GTJOAD

    Page Count: 9


    Baidya, DK
    Assistant professor, Indian Institute of Technology,

    Krishna, GM
    Manager, RITES, Highway Division, New Delhi,

    (Received 9 February 2000; accepted 16 April 2001)

    Abstract

    Influence of layering and presence of rigid boundary in the soil mass on natural frequency and resonant amplitude are studied experimentally by conducting model block vibration tests in vertical mode. Tests are conducted on different layered beds prepared in a tank using a model footing. A Lazan type mechanical oscillator is used for inducing vibration and two different materials (sand and sawdust) are used to form a layered system. In total, 180 tests are conducted in different layering combinations and different static and dynamic loading combinations, and several important observations are reported. Damping factors are found to be within 6.5% for the entire test series, which indicates that radiation damping is insignificant in the test system. It is also found that layering including layer position and thickness has significant effect on natural frequency. Observed natural frequencies are also compared with the predicted one based on static equivalent stiffness; encouraging agreement between observed and predicted values are found.


    Paper ID: GTJ11138J

    DOI: 10.1520/GTJ11138J

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    Author
    Title Investigation of Resonant Frequency and Amplitude of Vibrating Footing Resting on a Layered Soil System
    Symposium , 0000-00-00
    Committee D18