Article
Computer Science, Interdisciplinary Applications
Long Chen, Aibing Jin, Shunchuan Wu, Chaoqun Chu, Xue Li
Summary: This study establishes a three-dimensional model using the particle discrete element method and PFC3D software to simulate the spalling failure of rocks surrounding a deep buried tunnel. The results show that spalling failure mainly occurs at the spandrel and foot of the arch of the tunnel, with dense zones of intersection of fractures at the top and bottom of the tunnel. The magnitudes of the maximum and minimum in-situ principal stress, as well as the Poisson's ratio and post-peak behavior of the rock, influence the occurrence and depth of spalling failure.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Engineering, Geological
Zhao Wang, Tiehang Wang, Saisai Wu, Yanzhou Hao
Summary: This study presents a polygonal universal distinct element code grain-based model to investigate microcracking behaviors in rocks, which successfully simulates the evolution of cracks and macroscopic fracture patterns. The simulated results are consistent with laboratory tests, contributing to the improvement of rock acoustic emission monitoring and understanding of the damage process in rocks.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2021)
Article
Engineering, Mechanical
W. R. Hu, K. Liu, D. O. Potyondy, E. F. Salmi, E. J. Sellers, Q. B. Zhang
Summary: Dynamic shear rupture of rocks is important for earthquake fault formation and the stability of underground engineering structures. This study investigates shear strength, progressive fracturing, and seismicity of heterogeneous rock under dynamic loads. Experimental and simulation methods were used to examine the behavior of granite samples. The results confirmed the feasibility of the experimental setup and showed multi-scale fracturing and seismic activity during shear rupture. The findings also highlighted the influence of initial stress and strain rate on shear mechanical response and rupture behavior. The shear strength was approximated using the Mohr-Coulomb strength envelope under different conditions.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2023)
Article
Engineering, Mechanical
Ling He, Jiqing Huang, Yunxu Luo, Weiji Liu, Xiaohua Zhu, Sicheng Fan
Summary: This study investigates the ductile-brittle transition (DBT) behavior of polycrystalline diamond compact (PDC) bits in rock cutting through theoretical analysis and laboratory tests. Several indicators are determined to effectively reflect the DBT characteristics during rock breaking. The results have practical significance for the design and use of drilling bits in actual drilling processes.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2022)
Article
Construction & Building Technology
Yuhan Wang, Nhu H. T. Nguyen, Lianheng Zhao
Summary: Rock strainburst is a geological hazard that occurs under high triaxial stress states, and the axial stress has significant impacts on the strainburst process and micro-cracking behavior. As the axial stress increases, crack density and strainburst strength tend to increase, and there is a transition in strainburst crack mode from tensile dominated to tensile-shear mixed.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2021)
Article
Acoustics
Zhide Wang, Zuyao Ma, Yuanyou Xia, Xiong Zhou, Manqing Lin, Jie Li, Jinyuan Wang
Summary: This paper proposes a method to accurately determine the range of rock blasting fracture zone. By establishing a numerical analysis model based on the Mohr-Coulomb constitutive relationship and the Von Mises yield criterion, the range of the fracture zone and the maximum horizontal radius of the fracture zone are analyzed and obtained. Comparison of numerical analysis results with field measured data demonstrates the effectiveness of the proposed method, providing references for the safety control of blasting and excavation of rock slopes.
SHOCK AND VIBRATION
(2021)
Article
Engineering, Marine
Chang Xia, Zhen Liu, Cuiying Zhou
Summary: This study proposed an improved simulation method based on Burger's model and the Parallel Bonded model in PFC to simulate the full-stage creep process in soft rock. The numerical results showed good agreement with experimental results, with an average error of less than 3% throughout the entire creep process. The study also found that wing crack coalescence in soft rock is independent of the prefabricated crack angle, propagating with a fixed dip angle.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Geological
Xianyu Zhao, Derek Elsworth, Yunlong He, Wanrui Hu, Tao Wang
Summary: Grain texture characteristics have significant impacts on the anisotropy, strength, and ductility of crystalline rock. Researchers have proposed a grain texture model and incorporated it into granular mechanics modeling, successfully capturing major features of rock mechanical evolution, including the transition from brittle to ductile response.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Multidisciplinary
John M. Harmon, Konstantinos Karapiperis, Liuchi Li, Scott Moreland, Jose E. Andrade
Summary: This paper introduces the methodology of using the bonded particle method (BPM) with the level set discrete element method (LS-DEM-BPM) to model connected granular materials with arbitrary particle shape. Several examples are presented to demonstrate the method's application in different contexts, showing its potential predictive ability and insights into micromechanics. Additionally, advantages and disadvantages of the method are discussed.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Mathematics, Interdisciplinary Applications
Wangyang Li, Chong Shi, Cong Zhang
Summary: Dynamic semi-circular bending (SCB) experiments were conducted using a grain-based model based on particle flow code (PFC-GBM) and a split Hopkinson pressure bar (SHPB) system to investigate the impact of grain size on the rock's dynamic mechanical behaviors. Simulation results indicate that: (1) The strain rate waveform shows a double-hump shape when the particle size is less than 0.75 mm; (2) The reflection coefficient increases linearly with the grain-to-particle size ratio, while the transmission coefficient remains constant; and (3) Increasing grain-to-particle size ratio enhances particle migration within grains, leading to a decrease in crack number and dynamic tensile strength. The findings demonstrate the applicability of PFC-GBM in studying the dynamics of crystalline rock and provide insights for analyzing dynamic response on a microscopic scale.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Engineering, Chemical
Tarun De, Jayanta Chakraborty, Jitendra Kumar, Anurag Tripathi, Maitraye Sen, William Ketterhagen
Summary: Large scale industrial simulations of bulk solids often require the use of the Discrete Element Method, which can be computationally demanding due to the large number of particles involved. Coarse-graining techniques have been used to reduce the computational burden, but current methods typically employ a uniform coarse-grain ratio throughout the system. This limits the level of coarse-graining that can be achieved without sacrificing accuracy. To address this limitation, a multilevel coarse-graining technique that allows for spatial variation in the coarse-grain ratio has been proposed. In this study, a particle location based method for multi-level coarse-graining is introduced, which can be implemented using the open-source software LIGGGHTS Public. The efficiency of this method is demonstrated through successful simulations of discharge from a conical hopper, showing a significant reduction in computational time compared to uniform coarse-graining while maintaining accuracy.
Article
Engineering, Geological
Zbigniew Szkudlarek, Stanislaw Szweda
Summary: This article presents an analytical description of the process of rock discontinuity caused by an experimental cutting head. The use of cutting and loosening methods in combination is found to be more favorable compared to traditional mining methods. Analytical and numerical models were developed to analyze the impact of various parameters on the shape of the loosening line. The results confirmed the importance of proper design features of the cutting head in increasing the range of loosening.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Engineering, Environmental
Jaspreet Singh, Sarada Prasad Pradhan, Mahendra Singh, Lal Hruaikima
Summary: The existing structural discontinuities, such as faults, joints, and cleavages in rock slopes, play a crucial role in controlling the properties of the rock mass, and their presence is influenced by regional tectonic structures. The concept of damage, applied to intact rock and rock mass, refers to the degradation of their strength properties. A study conducted in the Garhwal Himalaya region revealed that damage caused by regional syncline resulted in high variability in fracture intensity and trace length away from the hinge zone.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Engineering, Civil
Benedek A. Logo, Balazs Vasarhelyi
Summary: This paper presents a theoretical relationship between the Poisson's ratio of intact rock and confining pressure, using the Hoek-Brown failure criteria, which can also be applied to rock mass using the Geological Strength Index (GSI).
PERIODICA POLYTECHNICA-CIVIL ENGINEERING
(2022)
Article
Engineering, Geological
J. Justo, H. Konietzky, J. Castro
Summary: This study numerically investigated the notch effect and the influence of grain size uniformity on the apparent fracture toughness of rocks. The results showed that increasing the notch radius led to an increase in the apparent fracture toughness.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
