A stress dilatancy relationship for coarse-grained soils incorporating particle breakage

2021 ◽  
Vol 24 (1) ◽  
Author(s):  
Er-Lu Wu ◽  
Jun-Gao Zhu ◽  
Shun-Bin He ◽  
Wen-Ming Peng
Keyword(s):  
Particle Breakage ◽  
Coarse Grained

scholarly journals Numerical Study of the Dynamic Compaction Process considering the Phenomenon of Particle Breakage

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xi Li ◽  
Jing Li ◽  
Xinyan Ma ◽  
Jidong Teng ◽  
Sheng Zhang
Keyword(s):  
Numerical Study ◽  
High Energy ◽  
Particle Breakage ◽  
Dynamic Compaction ◽  
Coarse Grained ◽  
Impact Stress ◽  
Logarithmic Curve ◽  
Before And After ◽  
Soil Foundation ◽  
Overlapping Method

Dynamic compaction (DC) is commonly used to strengthen the coarse grained soil foundation, where particle breakage of coarse soils is unavoidable under high-energy impacts. In this paper, a novel method of modeling DC progress was developed, which can realize particle breakage by impact stress. A particle failure criterion of critical stress is first employed. The “population balance” between particles before and after crushing is guaranteed by the overlapping method. The performance of the DC model is successfully validated against literature data. A series of DC tests were then carried out. The effect of particle breakage on key parameters of DC including crater depth and impact stress was discussed. Besides, it is observed that the relationship between breakage amount and tamping times can be expressed by a logarithmic curve. The present method will contribute to a better understanding of DC and benefit further research on the macro-micro mechanism of DC.

scholarly journals Particle breakage characteristics of coarse-grained soil under point-point contact

2020 ◽  
Vol 570 ◽  
pp. 032036
Author(s):  
L Li ◽  
C Zhao ◽  
Y W Zhang ◽  
G B Ouyang ◽  
S C Yu ◽  
...  
Keyword(s):  
Point Contact ◽  
Particle Breakage ◽  
Coarse Grained ◽  
Coarse Grained Soil

Study on Particle Breakage of Coarse-Grained Soil Based on Large-Scale Triaxial Test

2014 ◽  
Vol 937 ◽  
pp. 585-589
Author(s):  
Fu Yong Chu
Keyword(s):  
Power Function ◽  
Triaxial Test ◽  
Large Scale ◽  
Confining Pressure ◽  
Particle Breakage ◽  
Plastic Work ◽  
Coarse Grained ◽  
Earth Dam ◽  
Relationship Of ◽  
Coarse Grained Soil

Using large-scale shearing device, isotropiclly consolidated-drained triaxial test under different confining pressures are performed for overburden material of ShuangJiangKou earth dam which relative density is 0.8. The relationship between particle breakage of coarse-grained soil and input plastic work under loading and between particle breakage and confining pressure and between particle breakage and strength of coarse-grained soil. The results show that the particle breakage of coarse-grained soil and the input plastic work under loading is closely related. The particle breakage of coarse-grained soil increase with the input plastic work and there is a relationship of power function between Bg andWp. the increase of confining pressure will lead to the increase of particle breakage of coarse-grained soil, and there is a relationship of power function between Bg and. the increase of particle breakage of coarse-grained soil will lead to the decrease of strength of coarse-grained soil, and a relationship of linear between Bg andφ.

scholarly journals Effect of Particle Breakage and Shape on the Mechanical Behaviors of Granular Materials

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Yongxin Wang ◽  
Shengjun Shao ◽  
Zhi Wang
Keyword(s):  
Shear Strength ◽  
Granular Materials ◽  
Strain Curve ◽  
Friction Angle ◽  
Particle Breakage ◽  
Coarse Grained ◽  
Spherical Particles ◽  
Stable Configuration ◽  
Stress Strain ◽  
True Triaxial

The particle breakage property under loading is an important factor affecting the nonlinearity of the shear strength and stress-strain curves of coarse-grained soils. The macromechanical behaviors of coarse granular materials under consolidation and drainage shearing were tested by using a large true triaxial apparatus. The particle breakage mechanism has been analyzed by the fluctuation change of stress-strain curve and particle composition change. It was shown that the particle shape is an extremely important microproperty of the influence of granular material breakage. The variation rules of the internal friction angle and interlocking strength with the index of fine-grained breakage were sorted out, and the critical particle size for measuring the two friction modes under the given gradation was determined to be 1 mm. In addition, the numerical analysis was conducted by simulating the microshape parameters of particles. The conclusion is as follows: (1) The effect of shape parameters on shear strength can be simulated using the smoothness index Fd. (2) Compared with spherical particles, irregular-shaped particles lead to a decrease in the number of strong force chains. Moreover, more coordination numbers are needed to maintain a stable configuration, and the shear strength is improved.

scholarly journals Compaction Characteristics and Minimum Void Ratio Prediction Model for Gap-Graded Soil-Rock Mixture

2018 ◽  
Vol 8 (12) ◽  
pp. 2584 ◽  
Author(s):  
Tao Wang ◽  
Sihong Liu ◽  
Yan Feng ◽  
Jidu Yu
Keyword(s):  
Prediction Model ◽  
Void Ratio ◽  
Particle Breakage ◽  
Coarse Grained ◽  
Test Results ◽  
Inhomogeneous Materials ◽  
Compaction Characteristics ◽  
Fine Grained ◽  
Compaction Test

Gap-graded soil-rock mixtures (SRMs), composed of coarse-grained rocks and fine-grained soils particles, are very inhomogeneous materials and widely encountered in geoengineering. In geoengineering applications, it is necessary to know the compaction characteristics in order to estimate the minimum void ratio of gap-graded SRMs. In this paper, the void ratios of compacted SRMs as well as the particle breakage during vibrating compaction were investigated through a series of vibrating compaction tests. The test results show that gap-graded SRMs may reach a smaller void ratio than the SRM with a continuous gradation under some circumstances. When the particles in a gap interval play the role of filling components, the absence of them will increase the void ratio of the SRM. The particle breakage of gap-graded SRMs is more prominent than the SRM with continuous gradation on the whole, especially at the gap interval of 5–20 mm. Based on the test results, a minimum void ratio prediction model incorporating particle breakage during compaction is proposed. The developed model is evaluated by the compaction test results and its validation is discussed.

scholarly journals Mechanism of the Breakage of Spherical Gypsum Particles under 3-Point Contact Conditions

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1029
Author(s):  
Yiran Niu ◽  
Lin Li ◽  
Yanwei Zhang ◽  
Shicai Yu
Keyword(s):  
Great Influence ◽  
Point Contact ◽  
Particle Breakage ◽  
Coarse Grained ◽  
Spherical Particles ◽  
Superposition Method ◽  
Contact Conditions ◽  
Contact Points ◽  
Ball Contact ◽  
Coarse Grained Soil

Particle breakage has a great influence on the mechanical properties of coarse-grained soil materials. In the structure, a particle usually contacts with several surrounding particles when breakage occurs. The crushing mechanism of spherical particles under three-point contact conditions was investigated theoretically and experimentally. In the theoretical analysis, the contact force required for particle breakage is solved by using a stress superposition method based on the ball–ball contact model. To verify the theory, particle contact tests of gypsum spheres under three-point contact conditions were carried out. The experimental results are consistent with the theoretical prediction. Different from the ball–ball contact test, the rupture surface after breakage is a fixed plane passing through all three contact points under three-point contact conditions. Under multi-point contact conditions, the size of the conical core depends on the normal force on the contact point at the moment of particle breakage. Multi-point contact makes particle breakage more difficult, and the stronger the constraint of surrounding spheres, the more difficult it is for the particle to break. Both the theory and the experiment provide evidence that the arrangement of particles affects the overall strength of the coarse-grained soil structure.

Study on Particle Breakage and Strength Characteristic of Different Coarse-Grain Contents

2012 ◽  
Vol 246-247 ◽  
pp. 1037-1041
Author(s):  
Guang Jin Wang ◽  
Yue Tong Si ◽  
Xiang Yun Kong
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Large Scale ◽  
Particle Breakage ◽  
Coarse Grained ◽  
Stress Strain ◽  
Breakage Rate ◽  
Deep Soils ◽  
The Relationship ◽  
Coarse Grained Soil

The significant particle size grading and the particle breakage of deep soils are two major characteristics of super-high dumping-site. Based on the refitted large-scale direct shear experiments, this paper studied the particle breakage and shear strength of different coarse-grained soil. The experimental results indicates a conclusion: particle breakage index is very small when upright stress is less than 400kPa .The breakage rate increases obviously with the increase of upright stress. The particle breakage index is very little when coarse-grained contents are less than 46.0% .It increases significantly when coarse-grained contents are larger than 46.0%. Hyperbolic curves can express the relationship between particle breakage index and upright stress. The experiments studied on shear strength shows that the shear stress-strain curves are micro-softening model or micro-hardening model under low upright stress. The curves are slight-softening model at higher upright stress when the coarse-grained contents are equal to 24.0%. At coarse-grained contents equal 78.0%, the shear stress-strain curves are softening model under low upright stress. The shear strength envelope expressed nonlinear under higher upright stress.

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