Influence of Load Mode on Particle Crushing Characteristics of Silica Sand at High Stresses

Abstract

A series of high-pressure compression tests with various stress paths under monotonic and cyclic loadings were performed to examine the compression and particle crushing characteristics of silica sand in a dense state. Different stress paths were particularly designated to individually investigate the influences of mean and shear stress on particle crushing. Test results show that the degree of particle crushing increases with the stress level and is pronouncedly affected by the stress paths. For each compression test following a designated stress path, an increase in the cyclic loading number also enhances the degree of particle crushing.Particle morphology is affected by the accompanying occurrence and evolution of grain damage. Notably, the relative breakage expresses a liner relationship with the maximum volumetric strain during monotonic and repeated compression loadings. A good correlation between the relative breakage and plastic work per unit volume is obtained for silica sand at various mean stresses regardless of the stress history. However, this correlation is affected by cyclic loading number because of different crushing mechanisms. During the entire cyclic compression process, the increasing rate of relative breakage is lower than the plastic work increment for dense silica sand as the cyclic loading progresses.

Influential Factors of the Static Shear Properties of Coral Mud in the South China Sea

“…e mineral composition of coral mud is similar to that of calcareous sand, with up to 96% calcium carbonate. A large number of research studies have been devoted to investigating the factors influencing the shear properties of calcareous sand, including the confining pressure, density, particle breakage [4], and shear rate [5]. Studies have found that the shear characteristics of calcareous sand are greatly dependent on the confining pressure [6].…”

Laboratory Investigation on Particle Breakage Characteristics of Calcareous Sands

“…Internationally, scholars have adopted a wide range of methodologies/tools to study the crushing mechanism of calcified sand particles, including cyclic triaxial shearing [29], under drained and undrained triaxial compression [30], dynamic image analysis [31], and uniaxial compression [32], among others. In this paper, the uniaxial compression tests were carried out on the poor-graded calcareous sands collected from the Southern China Sea.…”

Bifurcation analysis of shear band in sand under true triaxial conditions with hypoplasticity

“…The onset of shear band is generally followed by the overall strength reduction of geomaterials. Meanwhile, the existing research has revealed that in some common cases the shear band can occur during the hardening stage of geomaterials, that is, before the peak strength of homogeneous deformation pattern is achieved 2–8 . Therefore, it is of importance in understanding the failure of geomaterials as well as geotechnical applications to accurately predicate the onset of shear band 9 …”