Dynamic Characteristics of Old Bay Clay

    Volume 20, Issue 4 (December 1997)

    ISSN: 0149-6115

    CODEN: GTJOAD

    Page Count: 11


    Guha, S
    Senior staff engineer, Kleinfelder, Diamond Bar, CA

    Drnevich, VP
    Professor and head, School of Civil Engineering, Purdue University, West Lafayette, IN

    Bray, JD
    Associate professor, University of California, Berkeley, CA

    Abstract

    Unusually strong ground motions at deep stiff clay sites in the East San Francisco Bay area during the 1989 Loma Prieta earthquake called for examination of the dynamic response of this clay deposit and characterization of its dynamic properties. In this paper, correlations of Old Bay clay dynamic properties with various soil parameters (e.g., plasticity, void ratio, magnitude and duration of confinement, consolidation stress history) are presented and compared with the existing database on cohesive soils. A special effort is made to evaluate the effects of sample disturbance on the laboratory measurement of dynamic properties of stiff cohesive soils. The laboratory measurement of low-strain shear modulus and damping ratios is adjusted by considering the aging of the Pleistocene era clay deposit. These adjustments, though effective, are not sufficient to account for the effects of structural disturbance. Shear modulus is reduced significantly by structural disturbance, but, surprisingly, the damping ratio is found to remain largely unaffected.


    Paper ID: GTJ10405J

    DOI: 10.1520/GTJ10405J

    ASTM International is a member of CrossRef.

    Author
    Title Dynamic Characteristics of Old Bay Clay
    Symposium , 0000-00-00
    Committee D18