Stiffness degradation and damping of carbonate and silica sands

J. Antonio Carraro, M.S. Bortolotto

    Research output: Chapter in Book/Conference paperConference paper

    10 Citations (Scopus)

    Abstract

    © 2015 Taylor & Francis Group, London. Stiffness and damping are some of the most important dynamic properties affecting wave propagation and small-strain response of soils. While these properties are useful in many geotechnical analyses, they are particularly relevant in analyses relying on the rigorous understanding of the mechanical behaviour of cyclically loaded soils, such as those affected by waves, wind loads and earthquakes. A fundamental understanding of such properties for offshore calcareous sediments still lacks as rigorous characterization of such properties is less established for these materials. In this study, a state-of-the-art resonant column apparatus is used to characterise the stiffness degradation and damping of a carbonate sand from the North West shelf of Australia. A silica sand with particle size distribution identical to that of the carbonate sand tested was also used to allow for the effect of soil mineralogy to be quantified. State variables such as density and mean effective stress were varied systematically to assess their effect on the stiffness degradation and damping ratio of the soils tested. Solid cylindrical specimens were subjected to mean effective stresses up to about 2MPas during the tests. Changes in particle size distribution were monitored to quantify particle breakage, which was shown to be higher for the carbonate sand than for the silica sand tested. At similar initial states of density and stress, increasing shear strains leads to a decrease in stiffness and corresponding increase in damping of the soils tested, as expected. However, the rate of stiffness degradation was always higher for the carbonate sand compared to its silica counterpart. At similar levels of stiffness degradation, the carbonate sand system-atically shows higher damping ratio than the silica sand.
    Original languageEnglish
    Title of host publicationFrontiers in Offshore Geotechnics III
    Place of PublicationLondon, UK
    PublisherCRC Press/Balkema
    Pages1179-1183
    Volume2015
    ISBN (Print)9781138028487
    Publication statusPublished - 2015
    Event3rd International Symposium on Frontiers in Offshore Geotechnics - Norway, Oslo, Norway
    Duration: 10 Jun 201512 Jun 2015
    Conference number: 3

    Conference

    Conference3rd International Symposium on Frontiers in Offshore Geotechnics
    Abbreviated titleISFOG
    CountryNorway
    CityOslo
    Period10/06/1512/06/15

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