Strong force networks in granular mixtures

Minh, Nguyen Hop; Cheng, Y. P.; Thornton, Colin

doi:10.1007/s10035-013-0455-3

Cited by 114 publications

(58 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5b), the α decreases while the β increases until FC * is reached (Table 3). At fines content below critical, the larger grains provide the active force chain [27], and increases in FC act to disrupt the direct contacts between large particles [43]; the stiffness of soils is determined by both the nature of the interparticle contacts and the interparticle coordination number [8,23]. Consequently, increasing the fines content decreases the interparticle contacts and coordination number between large particles, resulting in a decreasing α with increasing FC (i.e., a decrease in the stiffness of the mixture).…”

Section: The Variations Of α-Factors and β-Exponentsmentioning

confidence: 99%

Shear wave velocity of granular mixtures of silica particles as a function of finer fraction, size ratios and void ratios

Choo

Burns

2015

Granular Matter

View full text Add to dashboard Cite

This experimental investigation quantified the shear wave velocity (V s ) of granular packs composed of large grains mixed with small quantities of finer grains, up to the critical fines content (FC * ). Bender element tests were performed on 112 mixtures to quantify the variation of V s with fines content (FC), particle size ratio, and void ratio. When FC was less than FC * , the shear wave velocity decreased with increasing FC, due to the reduction in interparticle contacts between large grains. In addition, the observed reduction in packing stiffness was more apparent as the size difference between the two particles increased. Most notably, the results of this study demonstrated that V s of granular mixtures of two different silica particles with FC < FC * was best expressed in terms of intergranular void ratio when finer particles were treated as void space, as opposed to the global void ratio.

show abstract

Section: The Variations Of α-Factors and β-Exponentsmentioning

confidence: 99%

Shear wave velocity of granular mixtures of silica particles as a function of finer fraction, size ratios and void ratios

Choo

Burns

2015

Granular Matter

View full text Add to dashboard Cite

show abstract

“…The strong network is the main contributor to the deviator, whereas the weak network contributes to the isotropic component. A recent numerical study on imperfect binary mixtures, with particle size ratios (PSRs) up to 10 and higher, under uniaxial confined compression, considered the cumulative contribution to the deviator of the different contact-type networks (coarseto-coarse (c-c), coarse-to-fine (c-f) and fine-to-fine (f-f)), showing that contributions were dependent on the fines content (Minh et al, 2014). This paper uses the discrete-element method (DEM) to further extend previous numerical work on gap-graded materials to axisymmetric stress conditions, namely, triaxial test configuration, considered the most relevant conventional laboratory method to replicate stress field conditions in soil mechanics.…”

Section: Introductionmentioning

confidence: 99%

Force transmission and soil fabric of binary granular mixtures

et al. 2016

View full text Add to dashboard Cite

The effect of fines content on force transmission and fabric development of gap-graded mixtures under triaxial compression has been studied using the discrete-element method. Results were used to define load-bearing soil fabrics where the relative contributions of coarse and fine components are explicitly quantified in terms of force transmission. Comparison with previous findings suggests that lower particle size ratios result in higher interaction between components. A potential for instability was detected for underfilled fabrics in agreement with recent findings. It was also found that the threshold fines content provides an accurate macroscopic estimation of the transition between underfilled and overfilled fabrics.

show abstract

“…The stress-strain-strength response of silty sands is highly dependent on the involvement of both coarse and fine constituents in the load carrying microstructure of the mixture (e.g., [61,66]). For silt contents less than a particular threshold value known as the threshold fines content (i.e., FC th ), strong force networks of the load carrying microstructure mainly pass through the coarse particles that are dynamically in contact with each others.…”

Section: Equivalent Intergranular Void Ratiomentioning

confidence: 99%

“…It is well recognized that the liquefaction susceptibility is greatly influenced by sand initial state (taking into account the combined influence of density and mean principal effective stress) [4,35,37,76,89], shearing mode [8,62,98], and the overall particles shape [8,10,92]. Moreover, in particle scale, anisotropic microstructure of granular packing defined in terms of the statistical arrangement of particles and their associated contacts, as well as the general pattern of interaction between individual particles and their involvement in evolving force transmitting chains have central roles in soil shear strength and volume change response [19,51,52,61,66,80]. Based on the results of triaxial, simple shear, and hollow cylinder tests, the undrained (i.e., constant volume) stressstrain behavior of sandy soils can be categorized into three distinct types, as described below (see Fig.…”

Section: Introductionmentioning

confidence: 98%

Prediction of flow liquefaction instability of clean and silty sands

Lashkari

2015

Acta Geotech.

View full text Add to dashboard Cite

Adding a small amount of non-plastic silt to clean sands may lead to dramatic loss of shear strength and a noteworthy tendency toward contraction when the mechanical behavior of the mixture is compared with that of the clean host sand. Thus, simulation of the behavior of silty sands with varying fines content is still a challenging subject in geomechanics. A unified constitutive model for clean and silty sands is presented in this paper. To eliminate the factitious decrease of void ratio associated with inactive silt particles in various silty sand mixtures, the concept of equivalent void ratio is used in the model formulation instead of the global void ratio. In addition, the instantaneous soil state is expressed in terms of intergranular state parameter taking into account the combined influence of intergranular void ratio, mean principal effective stress and fines content. Then, dilatancy and plastic hardening modulus are directly linked to the intergranular state parameter. To improve the model capacity in simulation of cyclic tests, new features are added to the plastic hardening modulus. It is shown that the proposed model can reasonably reproduce the mechanical behavior as well as the onset of flow liquefaction instability of clean and silty sands using a unique set of parameters. List of symbolsA Dilatancy parameter (Eq. 22) B Model parameter (Eq. 31) b Fines participation factor (Eq. 2) c (=M e /M c ) Model parameter c h Plastic hardening parameter (Eq. 23) D pp , D pq , D qp , D qq See Eqs. (45)-(49) d Dilatancy function (Eq. 22) e Global void ratio e* Equivalent intergranular void ratio (Eq. 2) e 0

show abstract

Strong force networks in granular mixtures

Cited by 114 publications

References 9 publications

Shear wave velocity of granular mixtures of silica particles as a function of finer fraction, size ratios and void ratios

Shear wave velocity of granular mixtures of silica particles as a function of finer fraction, size ratios and void ratios

Force transmission and soil fabric of binary granular mixtures

Prediction of flow liquefaction instability of clean and silty sands

Contact Info

Product

Resources

About