### Abstract

A constitutive model for the stress-strain-time behavior of cohesive soils is developed using Cam-clay plasticity theory extended to include time-dependent effects. The model adopts the concept of separating the total deformation into immediate and delayed components. The immediate plastic deformation is evaluated by employing the associative flow rule on each of two distinct yield surfaces defined by the ellipsoid of the modified Cam-clay theory and the Von Mises cylinder inscribed in the Cam-clay ellipsoid. The delayed component of deformation is evaluated by employing the normality rule on equivalent ellipsoidal and cylindrical yield surfaces associated with the current state of stress of the soil and forcing the resulting creep strain rate tensor to satisfy phenomenological creep laws. In a companion paper by the same writers, the resulting constitutive equation is shown to predict the stress-strain-time behavior of wet clays more accurately than an earlier version based on a single-yield-surface formulation.

Original language | English (US) |
---|---|

Pages (from-to) | 1381-1401 |

Number of pages | 21 |

Journal | Journal of geotechnical engineering |

Volume | 116 |

Issue number | 9 |

State | Published - Sep 1990 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Engineering(all)

### Cite this

*Journal of geotechnical engineering*,

*116*(9), 1381-1401.

**Double-yield-surface Cam-clay plasticity model. I. Theory.** / Hsieh, H. S.; Kavazanjian, Edward; Borja, R. I.

Research output: Contribution to journal › Article

*Journal of geotechnical engineering*, vol. 116, no. 9, pp. 1381-1401.

}

TY - JOUR

T1 - Double-yield-surface Cam-clay plasticity model. I. Theory

AU - Hsieh, H. S.

AU - Kavazanjian, Edward

AU - Borja, R. I.

PY - 1990/9

Y1 - 1990/9

N2 - A constitutive model for the stress-strain-time behavior of cohesive soils is developed using Cam-clay plasticity theory extended to include time-dependent effects. The model adopts the concept of separating the total deformation into immediate and delayed components. The immediate plastic deformation is evaluated by employing the associative flow rule on each of two distinct yield surfaces defined by the ellipsoid of the modified Cam-clay theory and the Von Mises cylinder inscribed in the Cam-clay ellipsoid. The delayed component of deformation is evaluated by employing the normality rule on equivalent ellipsoidal and cylindrical yield surfaces associated with the current state of stress of the soil and forcing the resulting creep strain rate tensor to satisfy phenomenological creep laws. In a companion paper by the same writers, the resulting constitutive equation is shown to predict the stress-strain-time behavior of wet clays more accurately than an earlier version based on a single-yield-surface formulation.

AB - A constitutive model for the stress-strain-time behavior of cohesive soils is developed using Cam-clay plasticity theory extended to include time-dependent effects. The model adopts the concept of separating the total deformation into immediate and delayed components. The immediate plastic deformation is evaluated by employing the associative flow rule on each of two distinct yield surfaces defined by the ellipsoid of the modified Cam-clay theory and the Von Mises cylinder inscribed in the Cam-clay ellipsoid. The delayed component of deformation is evaluated by employing the normality rule on equivalent ellipsoidal and cylindrical yield surfaces associated with the current state of stress of the soil and forcing the resulting creep strain rate tensor to satisfy phenomenological creep laws. In a companion paper by the same writers, the resulting constitutive equation is shown to predict the stress-strain-time behavior of wet clays more accurately than an earlier version based on a single-yield-surface formulation.

UR - http://www.scopus.com/inward/record.url?scp=0025495169&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025495169&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0025495169

VL - 116

SP - 1381

EP - 1401

JO - Journal of Geotechnical and Geoenvironmental Engineering - ASCE

JF - Journal of Geotechnical and Geoenvironmental Engineering - ASCE

SN - 1090-0241

IS - 9

ER -