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

Abstract

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.

Prediction of Small‐Strain Dynamic Properties on Granulated Spherical Glass Bead‐Polyurethane Mixtures

“…Wichtmann and Triantafyllidis [18] proposed a formula that correlates Hardin's formula with uniformity coefficient (C u ) to examine the influence of the grain-size distribution on G max . Choo and Burns [21] introduced the critical fine content (FC * ) and intergranular void ratio (e ig ) to evaluate the property of shear wave velocity on packing of a granular mixture composed of large and small silica particle sizes. In addition, empirical formulas for estimating G max considering the effects of σ m ′ and rubber content on rubber-sand mixture were proposed [26,32].…”

“…Moreover, G max in most cases of proposed equations has been used as a reference value to estimate D min of soils. Although some researchers have studied the equations of dynamic properties for mixtures according to different particle sizes [20,21], there is a dearth of studies on the empirical equation to predict the dynamic properties considering the significant factors, such as σ m ′ , FC, e, and D 50 , for the binary mixtures composed of both plastic and nonplastic materials.…”

“…Packing (e) on G max . Choo and Burns [21] reported that the behavior of G max of the mixture cannot be expressed by a global void ratio (e) that defines the ratio of the volume of voids to volumes of small and large particles because e does not capture the mechanical behavior of large particles with smaller particles that are fully filled in the void formed by large particles. erefore, intergranular void ratio (e ig ) was defined by the ratio of the volumes of voids and small particles to the volume of large particles.…”

“…Its relation is quite complicated because these factors vary depending on the soil type and the ground conditions. Wichtmann et al [20] and Choo and Burns [21] studied the dynamic properties according to differences in fine content. ey suggested that G max is reduced by an increase in the fine content, in a way that depends on the specific fine content and particle-size ratio.…”

Yielding behaviour of cemented binary mixture

“…But, in-situ condition is closer to a mixture of clay, sand or silt. The properties of these binary mixtures are different from those pure clay or pure sand [1][2][3][4][5][6]. Literatures on the strength, stiffness and compressibility of these natural or untreated binary mixtures are available in abundant.…”