Centrifuge and large-scale modeling of seismic pore pressures in sands

Cyclic strain interpretation

Tarek Abdoun, M. A. Gonzalez, S. Thevanayagam, R. Dobry, A. Elgama, M. Zegha, V. M. Mercado, U. El Shamy

    Research output: Contribution to journalArticle

    Abstract

    Centrifuge modeling of pore pressure buildup in a sand deposit as a result of shaking is evaluated by comparison with a large-scale experiment. In large-scale Test SG-1, a 5.6-m-thick, mildly sloping deposit of hydraulic fill clean Ottawa sand of Dr=40%, was subjected to 5 s of low-intensity base shaking (<0.02g) that induced excess pore pressures short of liquefaction. Three centrifuge experiments using various soil deposits and saturation fluids were conducted and compared with the large-scale test. One of these centrifuge simulations used the same Ottawa sand andDr=40% of the prototype, a viscous pore fluid, and dry pluviation deposition, which created a soil fabric stiffer than the prototype. The other two centrifuge simulations used silty sand saturated with water. The pore pressure buildup in one of the silty sand tests was in good agreement with the prototype, while the other two centrifuge deposits did not develop any excess pore pressure. The various responses in the four tests are explained by various levels of cyclic soil shear strain using a cyclic strain approach. The cyclic strains in the two tests with no pore pressure were smaller than the threshold strain needed to start pore pressure generation in sands (<, 0.01%), while the cyclic strains in the two tests that built up pore pressure were greater than the threshold (0.03% > 0.01%). In addition, two more experiments using Ottawa sand were also conducted: a large-scale level-ground test and a centrifuge sloping test subjected to a greater excitation. The results of the six experiments including the two additional tests are very consistent, further verifying the validity of the strain approach and threshold strain for both levelground and mildly sloping-ground sites.

    Original languageEnglish (US)
    Pages (from-to)1215-1234
    Number of pages20
    JournalJournal of Geotechnical and Geoenvironmental Engineering
    Volume139
    Issue number8
    DOIs
    StatePublished - Aug 13 2013

    Fingerprint

    Pore pressure
    Centrifuges
    centrifuge
    pore pressure
    Sand
    sand
    Deposits
    modeling
    Experiments
    centrifugal model test
    experiment
    Hydraulics
    fill
    hydraulics
    test

    Keywords

    • Centrifuge
    • Cyclic strain
    • Dry pluviation
    • Earthquake
    • Hydraulic fill
    • Large scale
    • Liquefaction
    • Sand
    • Sand fabric
    • Shaking

    ASJC Scopus subject areas

    • Environmental Science(all)
    • Geotechnical Engineering and Engineering Geology

    Cite this

    Centrifuge and large-scale modeling of seismic pore pressures in sands : Cyclic strain interpretation. / Abdoun, Tarek; Gonzalez, M. A.; Thevanayagam, S.; Dobry, R.; Elgama, A.; Zegha, M.; Mercado, V. M.; Shamy, U. El.

    In: Journal of Geotechnical and Geoenvironmental Engineering, Vol. 139, No. 8, 13.08.2013, p. 1215-1234.

    Research output: Contribution to journalArticle

    Abdoun, T, Gonzalez, MA, Thevanayagam, S, Dobry, R, Elgama, A, Zegha, M, Mercado, VM & Shamy, UE 2013, 'Centrifuge and large-scale modeling of seismic pore pressures in sands: Cyclic strain interpretation', Journal of Geotechnical and Geoenvironmental Engineering, vol. 139, no. 8, pp. 1215-1234. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000821
    Abdoun, Tarek ; Gonzalez, M. A. ; Thevanayagam, S. ; Dobry, R. ; Elgama, A. ; Zegha, M. ; Mercado, V. M. ; Shamy, U. El. / Centrifuge and large-scale modeling of seismic pore pressures in sands : Cyclic strain interpretation. In: Journal of Geotechnical and Geoenvironmental Engineering. 2013 ; Vol. 139, No. 8. pp. 1215-1234.
    @article{ba3a3030927c4871baeda6636a8a0dc4,
    title = "Centrifuge and large-scale modeling of seismic pore pressures in sands: Cyclic strain interpretation",
    abstract = "Centrifuge modeling of pore pressure buildup in a sand deposit as a result of shaking is evaluated by comparison with a large-scale experiment. In large-scale Test SG-1, a 5.6-m-thick, mildly sloping deposit of hydraulic fill clean Ottawa sand of Dr=40{\%}, was subjected to 5 s of low-intensity base shaking (<0.02g) that induced excess pore pressures short of liquefaction. Three centrifuge experiments using various soil deposits and saturation fluids were conducted and compared with the large-scale test. One of these centrifuge simulations used the same Ottawa sand andDr=40{\%} of the prototype, a viscous pore fluid, and dry pluviation deposition, which created a soil fabric stiffer than the prototype. The other two centrifuge simulations used silty sand saturated with water. The pore pressure buildup in one of the silty sand tests was in good agreement with the prototype, while the other two centrifuge deposits did not develop any excess pore pressure. The various responses in the four tests are explained by various levels of cyclic soil shear strain using a cyclic strain approach. The cyclic strains in the two tests with no pore pressure were smaller than the threshold strain needed to start pore pressure generation in sands (<, 0.01{\%}), while the cyclic strains in the two tests that built up pore pressure were greater than the threshold (0.03{\%} > 0.01{\%}). In addition, two more experiments using Ottawa sand were also conducted: a large-scale level-ground test and a centrifuge sloping test subjected to a greater excitation. The results of the six experiments including the two additional tests are very consistent, further verifying the validity of the strain approach and threshold strain for both levelground and mildly sloping-ground sites.",
    keywords = "Centrifuge, Cyclic strain, Dry pluviation, Earthquake, Hydraulic fill, Large scale, Liquefaction, Sand, Sand fabric, Shaking",
    author = "Tarek Abdoun and Gonzalez, {M. A.} and S. Thevanayagam and R. Dobry and A. Elgama and M. Zegha and Mercado, {V. M.} and Shamy, {U. El}",
    year = "2013",
    month = "8",
    day = "13",
    doi = "10.1061/(ASCE)GT.1943-5606.0000821",
    language = "English (US)",
    volume = "139",
    pages = "1215--1234",
    journal = "Journal of Geotechnical and Geoenvironmental Engineering - ASCE",
    issn = "1090-0241",
    publisher = "American Society of Civil Engineers (ASCE)",
    number = "8",

    }

    TY - JOUR

    T1 - Centrifuge and large-scale modeling of seismic pore pressures in sands

    T2 - Cyclic strain interpretation

    AU - Abdoun, Tarek

    AU - Gonzalez, M. A.

    AU - Thevanayagam, S.

    AU - Dobry, R.

    AU - Elgama, A.

    AU - Zegha, M.

    AU - Mercado, V. M.

    AU - Shamy, U. El

    PY - 2013/8/13

    Y1 - 2013/8/13

    N2 - Centrifuge modeling of pore pressure buildup in a sand deposit as a result of shaking is evaluated by comparison with a large-scale experiment. In large-scale Test SG-1, a 5.6-m-thick, mildly sloping deposit of hydraulic fill clean Ottawa sand of Dr=40%, was subjected to 5 s of low-intensity base shaking (<0.02g) that induced excess pore pressures short of liquefaction. Three centrifuge experiments using various soil deposits and saturation fluids were conducted and compared with the large-scale test. One of these centrifuge simulations used the same Ottawa sand andDr=40% of the prototype, a viscous pore fluid, and dry pluviation deposition, which created a soil fabric stiffer than the prototype. The other two centrifuge simulations used silty sand saturated with water. The pore pressure buildup in one of the silty sand tests was in good agreement with the prototype, while the other two centrifuge deposits did not develop any excess pore pressure. The various responses in the four tests are explained by various levels of cyclic soil shear strain using a cyclic strain approach. The cyclic strains in the two tests with no pore pressure were smaller than the threshold strain needed to start pore pressure generation in sands (<, 0.01%), while the cyclic strains in the two tests that built up pore pressure were greater than the threshold (0.03% > 0.01%). In addition, two more experiments using Ottawa sand were also conducted: a large-scale level-ground test and a centrifuge sloping test subjected to a greater excitation. The results of the six experiments including the two additional tests are very consistent, further verifying the validity of the strain approach and threshold strain for both levelground and mildly sloping-ground sites.

    AB - Centrifuge modeling of pore pressure buildup in a sand deposit as a result of shaking is evaluated by comparison with a large-scale experiment. In large-scale Test SG-1, a 5.6-m-thick, mildly sloping deposit of hydraulic fill clean Ottawa sand of Dr=40%, was subjected to 5 s of low-intensity base shaking (<0.02g) that induced excess pore pressures short of liquefaction. Three centrifuge experiments using various soil deposits and saturation fluids were conducted and compared with the large-scale test. One of these centrifuge simulations used the same Ottawa sand andDr=40% of the prototype, a viscous pore fluid, and dry pluviation deposition, which created a soil fabric stiffer than the prototype. The other two centrifuge simulations used silty sand saturated with water. The pore pressure buildup in one of the silty sand tests was in good agreement with the prototype, while the other two centrifuge deposits did not develop any excess pore pressure. The various responses in the four tests are explained by various levels of cyclic soil shear strain using a cyclic strain approach. The cyclic strains in the two tests with no pore pressure were smaller than the threshold strain needed to start pore pressure generation in sands (<, 0.01%), while the cyclic strains in the two tests that built up pore pressure were greater than the threshold (0.03% > 0.01%). In addition, two more experiments using Ottawa sand were also conducted: a large-scale level-ground test and a centrifuge sloping test subjected to a greater excitation. The results of the six experiments including the two additional tests are very consistent, further verifying the validity of the strain approach and threshold strain for both levelground and mildly sloping-ground sites.

    KW - Centrifuge

    KW - Cyclic strain

    KW - Dry pluviation

    KW - Earthquake

    KW - Hydraulic fill

    KW - Large scale

    KW - Liquefaction

    KW - Sand

    KW - Sand fabric

    KW - Shaking

    UR - http://www.scopus.com/inward/record.url?scp=84881231410&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84881231410&partnerID=8YFLogxK

    U2 - 10.1061/(ASCE)GT.1943-5606.0000821

    DO - 10.1061/(ASCE)GT.1943-5606.0000821

    M3 - Article

    VL - 139

    SP - 1215

    EP - 1234

    JO - Journal of Geotechnical and Geoenvironmental Engineering - ASCE

    JF - Journal of Geotechnical and Geoenvironmental Engineering - ASCE

    SN - 1090-0241

    IS - 8

    ER -