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The effects of initial static deviatoric stress on liquefaction and pre-failure deformation characteristics of saturated sand under cyclic loading
https://orcid.org/0000-0003-2246-0430
https://orcid.org/0000-0001-6380-1188
Abstract Initial static deviatoric stress can affect the liquefaction behaviour and deformation characteristics of saturated sand under cyclic loading. A series of cyclic triaxial tests were performed on a saturated sand consolidated under a constant vertical stress but different lateral stresses. The dependence of failure mechanism, liquefaction resistance, and stiffness evolution of the sand on initial static deviatoric stress ratio was investigated on medium dense to dense sand samples (Dr = 0.44 to 0.82). The pre-failure deformation and the direction of strain accumulation were analysed under different static deviatoric stress ratios. The results indicate that under cyclic loading with stress reversal condition, the effective mean stress in the samples could reduce to zero, which leads to cyclic mobility failure and completely loss of stiffness due to liquefaction. The stress state after cyclic loading could be above critical state line. Under non reversal loading condition, however, the effective mean stress cannot reduce to zero and therefore the samples fail under shear due to large strain accumulation. In this condition, the stress state at the end of the cyclic loading is approximately at the critical state line and hardly affected by initial deviatoric stress. The failure resistance of medium dense to dense sand is not greatly affected by initial static deviatoric stress until it is large enough to meet non-reverse loading condition. The ratio of axial stain to excess pore water pressure accumulation (or Δϵacc a/Δϵacc v) increases with the average static deviatoric stress ratio η av. The strain accumulation direction roughly follows the flow rule of Modified Cam Clay model, independent of relative density and failure mechanism.
Highlights The cyclic behaviour of a sand are investigated under different initial static deviatoric stresses and relative densities. The pre-failure deformation and strain accumulation direction are discussed under an undrained condition. The flow direction of the sand under undrained cyclic loading roughly follows the flow rule of MCC.
The effects of initial static deviatoric stress on liquefaction and pre-failure deformation characteristics of saturated sand under cyclic loading
https://orcid.org/0000-0003-2246-0430
https://orcid.org/0000-0001-6380-1188
Abstract Initial static deviatoric stress can affect the liquefaction behaviour and deformation characteristics of saturated sand under cyclic loading. A series of cyclic triaxial tests were performed on a saturated sand consolidated under a constant vertical stress but different lateral stresses. The dependence of failure mechanism, liquefaction resistance, and stiffness evolution of the sand on initial static deviatoric stress ratio was investigated on medium dense to dense sand samples (Dr = 0.44 to 0.82). The pre-failure deformation and the direction of strain accumulation were analysed under different static deviatoric stress ratios. The results indicate that under cyclic loading with stress reversal condition, the effective mean stress in the samples could reduce to zero, which leads to cyclic mobility failure and completely loss of stiffness due to liquefaction. The stress state after cyclic loading could be above critical state line. Under non reversal loading condition, however, the effective mean stress cannot reduce to zero and therefore the samples fail under shear due to large strain accumulation. In this condition, the stress state at the end of the cyclic loading is approximately at the critical state line and hardly affected by initial deviatoric stress. The failure resistance of medium dense to dense sand is not greatly affected by initial static deviatoric stress until it is large enough to meet non-reverse loading condition. The ratio of axial stain to excess pore water pressure accumulation (or Δϵacc a/Δϵacc v) increases with the average static deviatoric stress ratio η av. The strain accumulation direction roughly follows the flow rule of Modified Cam Clay model, independent of relative density and failure mechanism.
Highlights The cyclic behaviour of a sand are investigated under different initial static deviatoric stresses and relative densities. The pre-failure deformation and strain accumulation direction are discussed under an undrained condition. The flow direction of the sand under undrained cyclic loading roughly follows the flow rule of MCC.
The effects of initial static deviatoric stress on liquefaction and pre-failure deformation characteristics of saturated sand under cyclic loading
https://orcid.org/0000-0003-2246-0430
https://orcid.org/0000-0001-6380-1188
Abstract Initial static deviatoric stress can affect the liquefaction behaviour and deformation characteristics of saturated sand under cyclic loading. A series of cyclic triaxial tests were performed on a saturated sand consolidated under a constant vertical stress but different lateral stresses. The dependence of failure mechanism, liquefaction resistance, and stiffness evolution of the sand on initial static deviatoric stress ratio was investigated on medium dense to dense sand samples (Dr = 0.44 to 0.82). The pre-failure deformation and the direction of strain accumulation were analysed under different static deviatoric stress ratios. The results indicate that under cyclic loading with stress reversal condition, the effective mean stress in the samples could reduce to zero, which leads to cyclic mobility failure and completely loss of stiffness due to liquefaction. The stress state after cyclic loading could be above critical state line. Under non reversal loading condition, however, the effective mean stress cannot reduce to zero and therefore the samples fail under shear due to large strain accumulation. In this condition, the stress state at the end of the cyclic loading is approximately at the critical state line and hardly affected by initial deviatoric stress. The failure resistance of medium dense to dense sand is not greatly affected by initial static deviatoric stress until it is large enough to meet non-reverse loading condition. The ratio of axial stain to excess pore water pressure accumulation (or Δϵacc a/Δϵacc v) increases with the average static deviatoric stress ratio η av. The strain accumulation direction roughly follows the flow rule of Modified Cam Clay model, independent of relative density and failure mechanism.
Highlights The cyclic behaviour of a sand are investigated under different initial static deviatoric stresses and relative densities. The pre-failure deformation and strain accumulation direction are discussed under an undrained condition. The flow direction of the sand under undrained cyclic loading roughly follows the flow rule of MCC.
The effects of initial static deviatoric stress on liquefaction and pre-failure deformation characteristics of saturated sand under cyclic loading
Liu, Zhiyong (author) / Qian, Jiangu (author) / Yaghoubi, Mohammadjavad (author) / Xue, Jianfeng (author)
2021-06-17
Article (Journal)
Electronic Resource
English
Comparison of Deformation Behavior of Saturated Sand under Constant and Variable Deviatoric Stress
| Springer Verlag | 2020
The specific deviatoric energy to liquefaction in saturated cyclic triaxial tests
| BASE | 2019