A DEM study of the effect of the loss of fine particles on the mechanical behavior of gap-graded soils

Taha, Habib; Nguyen, Ngoc‐Son; Marot, Didier; Hijazi, Abbas; Abou-Saleh, Khalil

doi:10.1016/j.gete.2021.100305

Cited by 11 publications

(5 citation statements)

References 31 publications

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“…It is observed that strong contacts sustain the majority (>80%) of the external loadings, especially the deviatoric stress. For example, the strong contacts in the non-eroded R100A140 specimen sustain the majority (84%) of the mean effective stress σ' p and almost all (99%) deviatoric stress σ q (Figure 17B,C), which is in accordance with Taha et al 71 Note that although weak contacts sustain only a small portion of the mean effective stress, they may facilitate the stability of the soil structure, as observed in Wautier et al 60 and Ma et al 12 The contribution of strong contacts to σ' p evolves smaller with effective confining stress and stress ratio, inferring that particles are more susceptible to suffusion under higher confining pressure and initial stress anisotropy, which echoes the observation in Figure 10. In addition, seepage changes the soil structure and results in the decreasing proportion of strong contact networks in force transmission for all specimens.…”

Section: Characteristics Of Force Chain Network and Void Spacessupporting

confidence: 89%

“…It is observed that strong contacts sustain the majority (>80%) of the external loadings, especially the deviatoric stress. For example, the strong contacts in the non‐eroded R100A140 specimen sustain the majority (84%) of the mean effective stress σ' p and almost all (99%) deviatoric stress σ q (Figure 17B,C), which is in accordance with Taha et al 71 . Note that although weak contacts sustain only a small portion of the mean effective stress, they may facilitate the stability of the soil structure, as observed in Wautier et al 60 .…”

Section: Microscopic Inspections During Seepage Infiltrationsupporting

confidence: 86%

“…):

\begin{equation} {\bm{\sigma}}_{\textit{net}}=\frac{1}{V}\sum _{c\in \textit{net}}{\mathbf{F}}^{c}{\mathbf{d}}^{c} \end{equation}

where net refers to the strong and weak contact networks or the C‐C , F‐F and C‐F contact networks of soil matrix; V is the total volume of the specimen; F c is the contact force; d c is the branch vector connecting the centroids of two contacted particles. The contribution of each contact network to the mean effective stress σ' p and deviatoric stress σ q , that is,

c_{net}^p

and

c_{net}^q

, can be obtained as Taha et al 71

\begin{equation} {c}_{\textit{net}}^{p}=\sigma {}_{p,\textit{net}}^{\prime}/\sigma {}_{p}^{\prime}\mathrm{and}{c}_{\textit{net}}^{q}={\sigma}_{q,\textit{net}}/{\sigma}_{q} \end{equation}

where

\begin{equation} \sigma {}_{p,\textit{net}}^{\prime}=\frac{1}{3}{\sigma}_{\textit{ii},\textit{net}},{\sigma}_{q,\textit{net}}=\sqrt{\frac{3}{2}{\bm{\sigma}}_{\textit{net}}^{\prime}{\bm{\sigma}}_{\textit{net}}^{\prime}} \end{equation}

and

σ_{p}^{'} badbreak= \frac{1}{3} σ_{ii}, σ_{q} goodbreak= \sqrt{\frac{3}{2} {bold-italicσ}^{'}}

…”

Section: Microscopic Inspections During Seepage Infiltrationmentioning

confidence: 99%

“…where net refers to the strong and weak contact networks or the C-C, F-F and C-F contact networks of soil matrix; V is the total volume of the specimen; F c is the contact force; d c is the branch vector connecting the centroids of two contacted particles. The contribution of each contact network to the mean effective stress σ' p and deviatoric stress σ q , that is, 𝑐 𝑝 𝑛𝑒𝑡 and 𝑐 𝑞 𝑛𝑒𝑡 , can be obtained as Taha et al 71 :…”

Section: Characteristics Of Force Chain Network and Void Spacesmentioning

confidence: 99%

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A resolved CFD–DEM investigation into the onset of suffusion: effect of confining pressure and stress anisotropy

Chen,

Hu,

Yang

et al. 2023

Num Anal Meth Geomechanics

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The susceptibility of a granular soil to suffusion is strongly dependent on its grain size distribution (GSD) and the mechanical and hydraulic conditions it is subjected to. This study investigates the onset of suffusion considering the effect of confining pressure and stress anisotropy using a fully resolved computational fluid dynamics and discrete element method (CFD–DEM). Three benchmarks, including the sedimentations of single and two adjacent spheres and the classic one‐dimensional (1D) consolidation are performed to demonstrate the capability of this method for high‐fidelity particle‐fluid simulations. A modified hydraulic criterion for the onset of suffusion considering stress anisotropy is presented. The microstructural changes of soil specimens before and during global suffusion are inspected, with emphasis on the evolutions of particle kinetic energy and displacements, force chain networks, and stress anisotropy. We found that the critical hydraulic gradient is negatively correlated with the confining pressure and the degree of stress anisotropy. Fine particles in the soil matrix are locally detached at small hydraulic gradients before the apparent global suffusion, as manifested by the variation of particle kinetic energy and coordination numbers. The roles of different contact types on force transmission and stress anisotropy in eroded specimens are also examined.

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Section: Characteristics Of Force Chain Network and Void Spacessupporting

confidence: 89%

Section: Microscopic Inspections During Seepage Infiltrationsupporting

confidence: 86%

“…):

\begin{equation} {\bm{\sigma}}_{\textit{net}}=\frac{1}{V}\sum _{c\in \textit{net}}{\mathbf{F}}^{c}{\mathbf{d}}^{c} \end{equation}

c_{net}^p

and

c_{net}^q

, can be obtained as Taha et al 71

\begin{equation} {c}_{\textit{net}}^{p}=\sigma {}_{p,\textit{net}}^{\prime}/\sigma {}_{p}^{\prime}\mathrm{and}{c}_{\textit{net}}^{q}={\sigma}_{q,\textit{net}}/{\sigma}_{q} \end{equation}

where

\begin{equation} \sigma {}_{p,\textit{net}}^{\prime}=\frac{1}{3}{\sigma}_{\textit{ii},\textit{net}},{\sigma}_{q,\textit{net}}=\sqrt{\frac{3}{2}{\bm{\sigma}}_{\textit{net}}^{\prime}{\bm{\sigma}}_{\textit{net}}^{\prime}} \end{equation}

and

σ_{p}^{'} badbreak= \frac{1}{3} σ_{ii}, σ_{q} goodbreak= \sqrt{\frac{3}{2} {bold-italicσ}^{'}}

…”

Section: Microscopic Inspections During Seepage Infiltrationmentioning

confidence: 99%

Section: Characteristics Of Force Chain Network and Void Spacesmentioning

confidence: 99%

See 2 more Smart Citations

A resolved CFD–DEM investigation into the onset of suffusion: effect of confining pressure and stress anisotropy

Chen,

Hu,

Yang

et al. 2023

Num Anal Meth Geomechanics

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show abstract

“…undrained behavior [29,31,[38][39] and sedimentation [40] have been evaluated. These studies have stated that the global void ratio is not suitable for describing the load-bearing structure of soil and recommend the use of the intergranular void ratio.…”

Section: Introductionmentioning

confidence: 99%

The role of fines content and particle size ratio on the load-bearing structure of binary granular soil: A micromechanical approach

Nia,

Bayesteh,

Khodaparast

2024

Preprint

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The particle size ratio and fines content are the most important factors influencing the behavior of binary graded granular soil. Previous studies have focused more on the effects of the fabric, particle size distribution and fines content on the macroscopic response of binary mixtures. The effect of the fines participation factor (β) on the load-bearing structure of binary graded soil and estimation of this parameter (β) from the macro and micromechanical perspectives have rarely been evaluated. The present study used a micro-mechanical approach and DEM to evaluate the global void ratio (e), intergranular void ratio (e*) and the contribution of the fines content to the load-bearing structure of binary graded soil during drained and undrained tests. The effects of the particle size ratio, fines content, initial packing density and confining pressure on β also have been evaluated. The results showed that e* is a more reliable parameter than e for interpreting the behavior of binary graded soil. In a binary graded mixture that contains coarse and fine grains, β increased non-linearly and lower values of β were obtained for denser samples. With an increase in the particle size ratio, the values of β and microscopic parameters such as the coarse-fine (C-F) particle contact decreased. The decrease in the C-F particle contact caused a decrease in β. An equation is proposed to estimate β based on the fines content and particle size ratio of the binary mixtures.

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Study on particle loss-induced deformation of gap-graded soils: role of particle stress

Cheng,

Ping,

Han

et al. 2024

Acta Geotech.

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A DEM study of the effect of the loss of fine particles on the mechanical behavior of gap-graded soils

Cited by 11 publications

References 31 publications

A resolved CFD–DEM investigation into the onset of suffusion: effect of confining pressure and stress anisotropy

A resolved CFD–DEM investigation into the onset of suffusion: effect of confining pressure and stress anisotropy

The role of fines content and particle size ratio on the load-bearing structure of binary granular soil: A micromechanical approach

Study on particle loss-induced deformation of gap-graded soils: role of particle stress

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