Article
Engineering, Environmental
Du-min Kuang, Zhi-lin Long, Rui-qi Guo, Tao Zhao, Kai Wu
Summary: This study aims to investigate the rate-dependent breakage behavior of calcareous sand particles. Experimental tests showed that particle crushing strengths follow the Weibull distribution, and an increase in loading rates results in changes in fragmentation modes. Simulation results revealed that fractures initiate near contact points and higher loading rate leads to increased particle breakage.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Engineering, Civil
Houzhen Wei, Hao Liu, Xiaoxiao Li, Zhao Tao, Yongjie Wu, Jianhua Shen, Mei Yin
Summary: This study investigates the mechanical behavior of calcareous sand under different stress paths. The results show that consolidation pressure and stress path have significant effects on the volume strain, strength, and particle breakage of calcareous sand.
Article
Geosciences, Multidisciplinary
Yongtao Zhang, Ruiyuan Zhang, Chengcheng Yu, Huiwu Luo, Zhiqiang Deng
Summary: For the island and reef project formed by filling calcareous sand, triaxial shear tests were conducted on five different typical particle size distributions (PSDs) to obtain mechanical parameters. The results showed that narrower particle gradation resulted in a decrease in axial strain at strain-softening point, while confining pressure had a significant impact on the volumetric deformation modulus. The study also verified the feasibility of numerical simulation and rationality of parameter calibration.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Engineering, Geological
Shao-Heng He, Hua-Feng Shan, Tang-Dai Xia, Zhi-Jun Liu, Zhi Ding, Fan Xia
Summary: This study investigates the effect of temperature on the drained shear behavior of calcareous sand. The results show that an increase in temperature aggravates particle breakage, affecting the strength and dilatancy of the sand. A stress-dilatancy equation and an empirical model for phi(cs) were proposed based on the experimental findings.
Article
Engineering, Mechanical
Sudheer Prabhu, Tong Qiu
Summary: The discrete element method has been used to study the micro-mechanical behavior of sand with upscaled particle size distribution in order to reduce computational cost, but the impact of particle breakage at high stresses on dynamic sand response is still not well understood. Results show that well-calibrated parameters can provide similar dynamic stress-strain response with upscaled PSD specimens, emphasizing the importance of considering particle breakage in stress-strain response under high stresses.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2021)
Article
Engineering, Geological
Du-Min Kuang, Zhi-Lin Long, Ikechukwu Ogwu, Zhuo Chen
Summary: The study proposed a particle breakage simulation approach based on the discrete element method framework, modeling the variability of particle breakage strength with the invertible function method to avoid local stress generation and non-conservation of mass and volume, and eliminating the need for a predefined fragmentation mode.
Article
Engineering, Chemical
Zhedan Gong, Yang Yang, Lijie Cui, Jinlong He, Xiaoxing Liu
Summary: In this study, the size effect in the fragmentation strength of cylindrical alumina aggregate under quasi-static diametrical loading is investigated using Discrete Element Method (DEM) simulations. It is found that tensile stress concentration develops in the inner margin of the damage zone, leading to the emergence and propagation of diametrical crack and catastrophic splitting of the aggregate. Both the fragmentation strength and the dimensionless damage zone size decrease to limit values, and the latter is around 0.1. The DEM simulations suggest that the formation of damage zones adjacent to the loading points induces the size effect in the fragmentation of intact aggregate.
Article
Energy & Fuels
Yan Gao, Junyuan Yu, Youbao Wang, Wenlong Li, Tiangen Shi
Summary: The simulation results based on the discrete element method indicate that the particle breakage of calcareous sand has a significant influence on soil stress and pile tip resistance. However, it has limited effect on the variation of particle contact normal directions. The stresses in calcareous sand are lower compared to siliceous sand, which makes pile foundation more prone to failure.
Article
Engineering, Marine
Yu Peng, Xuanming Ding, Zhen-Yu Yin, Pei Wang
Summary: This study investigates the microscopic mechanism of pile penetration in crushable granular soils, with a focus on the role of particle corner breakage. Experimental tests and DEM simulations were conducted to analyze the behavior of piles in coral sand. The findings reveal that the particular shrinkage of friction resistance in coral sand is attributed to the dual effect of corners. Increasing confining pressure does not effectively improve the friction-bearing capacity of piles. The diagram describing the relationship between corner breakage and effective contacts provides insights into the force transmission in soil. The study also highlights the impact of grain angularity on particle breakage within a shear zone.
Article
Geochemistry & Geophysics
Baojian Li, Panpan Guo, Gaoyun Zhou, Zhe Wang, Gang Lei, Xiaonan Gong
Summary: Through undrained cyclic triaxial tests, it was found that calcareous sand with different relative densities have varying cyclic responses under static shear stress. Dense sand has greater cyclic resistance than loose sand, but the initial static stress affects the cyclic resistance differently for the two types of sand. Dense sand dissipates energy more quickly, while loose sand reaches the lowest cyclic resistance at a static shear stress of 0.12.
Article
Mathematics, Interdisciplinary Applications
Alan A. de Arruda Tino, Luis Marcelo Tavares
Summary: Several tests are commonly used in the mining and aggregate industries to analyze the resistance of rocks and ores to breakage, providing basis for mathematical expressions or models. This study shows that simulations using the discrete element method with polyhedral particles can predict outcomes of three specific tests, with sensitivity analysis recommending optimal values for the drop weight test. The validity of the breakage model and its ability to describe test outcomes for brittle particulate materials are demonstrated.
COMPUTATIONAL PARTICLE MECHANICS
(2022)
Article
Geochemistry & Geophysics
Qiang Ou, Yifu Li, Yang Yang, Zhaogang Luo, Shaokang Han, Tan Zou
Summary: This study investigates the mechanical property of biomodified geogrid to improve the effectiveness of reinforcement of calcareous sand. The strength and deformation of the reinforced specimens are closely related to the geogrid layer, times of biotreatment, and confining pressure. Interactions between geogrid ribs and calcareous sand particles are crucial for understanding the mechanical mechanism of BGRCS.
Article
Engineering, Environmental
Xue Li, Jiankun Liu, Jinze Li
Summary: This study investigates the fractal dimension, particle shape, and particle breakage of calcareous sand under multi-level ending pressure. The compression behavior of calcareous sand is similar to that of silt soil, with significant particle breakage occurring under high-stress levels. The shape indexes, such as sphericity, aspect ratio, convexity, and overall regularity, increase with increasing axial stress or decreasing average grain size. The surface and mass fractal dimensions of the tested specimens range from 1.12 to 1.93 and from 2.14 to 2.92, respectively. The fractal dimensions and relative breakage ratio increase logarithmically with increasing axial stress. Additionally, an increase in average grain size leads to an increase in the relative breakage ratio and a decrease in fractal dimension. There is a linear relationship between surface or mass fractal dimension and relative breakage ratio.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Engineering, Chemical
Sheng Zhang, Jia-Lu Wang, Chen-Xi Tong
Summary: This paper presents a breakage matrix approach to investigate the evolution of particle size distribution in granular materials. It is found that the breakage-induced particle size distribution tends to be fractally distributed and the degree of particle breakage is linearly related to the input work.
Article
Engineering, Geological
Ni An, Gang Ma, Heng Zhou, Di Wang, Xi Lu, Wei Zhou
Summary: The study investigates the scale effect mechanism of sandy gravel material from Dashixia rockfill dam in China using the discrete element method (DEM). The results show that particle breakage weakens the shear strength of the material, while the widening of particle size distribution increases the resistance to deformation.
Article
Engineering, Mechanical
Ruiqi Guo, Huiqi Ren, Lei Zhang, Zhilin Long, Xiquan Jiang, Xiangyun Wu, Hailu Wang
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2020)
Article
Engineering, Environmental
Du-min Kuang, Zhi-lin Long, Rui-qi Guo, Tao Zhao, Kai Wu
Summary: This study aims to investigate the rate-dependent breakage behavior of calcareous sand particles. Experimental tests showed that particle crushing strengths follow the Weibull distribution, and an increase in loading rates results in changes in fragmentation modes. Simulation results revealed that fractures initiate near contact points and higher loading rate leads to increased particle breakage.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Materials Science, Multidisciplinary
Ruiqi Guo, Huiqi Ren, Lei Zhang, Zhilin Long, Xiangyun Wu, Hailu Wang
Summary: This study designed a split Hopkinson pressure bar (SHPB) device in a two-by-two form to meet the demand for dynamic mechanical experiments on brittle materials, and studied stress waveforms generated by impacting different types of bars through numerical simulation. Comparison analysis based on concrete models showed that the introduced two-by-two form SHPB device can reduce wave dispersion effects and is suitable for dynamic mechanical experiments on heterogeneous materials like concrete.
ACTA MECHANICA SOLIDA SINICA
(2021)
Article
Engineering, Civil
Yang Cai, Hui-qi Ren, Zhi-lin Long, Rui-qi Guo, Kuang-min Du, Sha-sha Chen, Zhi-hao Zheng
Summary: This study investigates the dynamic mechanical properties of coral aggregate concrete (CAC) and compares it with ordinary Portland cement concrete (OPC). The results show significant differences between CAC and OPC in terms of failure pattern, particle evolution, and dynamic increase factor under high strain rate loading. Additionally, CAC exhibits a brittle-ductile transition under dynamic loading, with lower impact toughness and energy absorption capacity compared to OPC.
Article
Engineering, Civil
Jinlei Sun, Wenchao Ma, Ruiqi Guo, Yanhuai Ding, Bing Liu
Summary: The dynamic mechanical properties of high-strength all-coral-sand seawater concrete (HCSC) were studied by optimizing the mix ratio of polyvinyl alcohol (PVA) fibers and copper-coated steel (CCS) fibers. The results showed that blending PVA and CCS fibers improved the compressive and impact compression strength of HCSC. The study also revealed the correlation between strain rate and dynamic strength increase factor (DIF), as well as the relationship between energy properties and strain rate. Optimizing the volume content of PVA and CCS fibers enhanced the impact resistance of HCSC.
Article
Computer Science, Theory & Methods
Ruiqi Guo, Yingxiong Xiao
INTERNATIONAL JOURNAL OF MODELING SIMULATION AND SCIENTIFIC COMPUTING
(2020)