Journal articles: 'Rock breakage'

1

Jiang, Hongxiang, Zhiyuan Cai, Ouguo Wang, and Deguang Meng. "Experimental and Numerical Investigation of Hard Rock Breakage by Indenter Impact." Shock and Vibration 2020 (May 18, 2020): 1–12. http://dx.doi.org/10.1155/2020/2747830.

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To investigate the effect of indenter shape, impact energy, and impact velocity on the rock breakage performance, a test device for rock fragmentation by indenter impact was developed to obtain the rock breakage volume, depth, and area under different impact conditions. By comparing the rock breakage volume, depth, area, and specific energy consumption, the results show that indenter shape has a greater influence on the rock breakage performance than that of the impact velocity with the same impact energy, and impact energy plays a decisive role in rock breakage performance with an identical indenter shape and impact velocity. For the lowest to highest specific energy consumption, the order of indenter shape is cusp-conical, warhead, hemispherical, spherical-arc, and flat-top under the same impact energy and velocity, but the cusp-conical indenter is damaged after several impacts. The rock breakage volume, depth, and area all increase with the increase in impact energy, but the effect of the impact velocity could be ignored under the same impact energy. In addition, the rock breakage features of the numerical simulation and experiments are similar, which show that the crushing zone close to the indenter impact point is mainly caused by the high compressive stress, and then radial cracks are caused by the accumulative energy release. The findings of this study will contribute to progress in the performance and efficiency for percussive rock drilling.

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Dessouki, Amr El, and Hani Mitri. "Rock Breakage Using Expansive Cement." Engineering 03, no. 02 (2011): 168–73. http://dx.doi.org/10.4236/eng.2011.32020.

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Jiang, Hongxiang, and Deguang Meng. "Experimental Research on the Specific Energy Consumption of Rock Breakage Using Different Waterjet-Assisted Cutting Heads." Advances in Materials Science and Engineering 2018 (2018): 1–11. http://dx.doi.org/10.1155/2018/3853980.

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To investigate the specific energy consumption (SE) of rock breakage by cutting heads assisted by different types of waterjet and to identify optimal waterjet parameters and assistance types, rock cutting with and without waterjets was carried on a rock fragmentation test bed. SE is a comprehensive evaluation index and was developed according to the applied load on cutting head, and the SE under different cutting conditions was compared and analyzed. The results show that the SE of rock breakage without waterjet assistance increased with the increasing of rock compressive strength (RCS) but that the limited drilling depth decreased. The effect of the waterjet pressure on the SE of rock breakage by the cutting head I was marked, and SE decreased by 30∼40% when the ratio between RCS and waterjet pressure was less than 1. However, the function of the waterjet assistance was poor; therefore, a ratio of 1 could be used to distinguish the rock breakage effect of cutting head I. For cutting head II, the rock damage from the waterjet impact was limited due to the large waterjet standoff distance; thus the rock breakage performance of cutting head II was also limited. The waterjet impacting at the tip of the conical pick using cutting head III could enter into the cracks caused by the mechanical pick and fracture the rock. Therefore, the rock breakage performance of cutting head III was better than that of cutting head II.

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Al-Bakri, Ali, and Mohammed Hefni. "A review of some nonexplosive alternative methods to conventional rock blasting." Open Geosciences 13, no. 1 (January 1, 2021): 431–42. http://dx.doi.org/10.1515/geo-2020-0245.

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Abstract The conventional blasting rock excavation method is the main means of rock breakage because of its high productivity, and it is relatively inexpensive compared to other methods. However, it raises safety concerns and can negatively impact the environment. The major disturbances that may be induced by this method include flyrock, gas emissions, and vibrations. This review discusses some nonexplosive rock breakage methods, particularly the hydraulic splitter and expansive chemical agents, that can be employed instead of the conventional blasting method and analyzes their potential effectiveness in rock breakage. Hydraulic splitting machines and expansive chemical agents were studied in the context of the literature. This review showed that hard rock breaking can be executed effectively and safely using alternative methods, which have a wide range of advantages, including safe operation, ease of use, and environmental friendliness, over conventional explosive methods. Moreover, as modern nonexplosive methods, hydraulic splitting machines and expansive chemical agents can generate pressure of up to 43 and 30–44 MPa to induce stresses in rocks, respectively. Owing to safety and environmental restrictions on conventional blasting, the application scope of the modern methods can be increased in the future.

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Xu, Ying, Xiekang Zhou, and Weimei Gong. "Mechanism and Control of Cable Breakage in a Roadway with Thick Top Coal in a Rockburst Mine." Advances in Civil Engineering 2021 (June 12, 2021): 1–12. http://dx.doi.org/10.1155/2021/2275820.

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Because top coal is not stable, a roadway with thick top coal often appears to mine pressure problems, such as bolt failure, cable breakage, and roof caving. In particular, these problems are more serious in rockburst mines. Based on a cable breakage case of No. 3 roadway in Xingcun coal mine, the paper analyzed the stress and elastic energy evolution law of surrounding rock and stress state of cable in the 3# roadway by means of the numerical simulation method. Thus, the cable breakage mechanism of the roadway with thick top coal in rockburst mine was revealed. Then, because surrounding rock grouting can reduce the stress concentration of surrounding rock and cable, surrounding rock grouting technology was proposed as control technology of cable breakage. Finally, parameters of surrounding rock grouting were designed and applied in the No. 3 roadway. The field results showed that surrounding rock grouting technology can be one of the solutions for cable breakage of roadway with thick top coal in rockburst mine. The research results of this paper can provide certain theoretical and practical value for mine pressure control of roadway.

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Vazhov, V. F., S. Y. Datskevich, M. Y. Zhurkov, V. M. Muratov, and B. Jeffryes. "Discharge-mechanical method of rock breakage." Journal of Physics: Conference Series 830 (May 4, 2017): 012148. http://dx.doi.org/10.1088/1742-6596/830/1/012148.

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Chappell, B. A. "Anisotropy in jointed rock mass breakage." Mining Science and Technology 8, no. 1 (January 1989): 1–19. http://dx.doi.org/10.1016/s0167-9031(89)90869-4.

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Vazhov, V. F., V. M. Muratov, B. S. Levchenko, S. S. Pel’tsman, D. V. Zhgun, and A. M. Adam. "Rock breakage by pulsed electric discharges." Journal of Mining Science 48, no. 2 (March 2012): 308–13. http://dx.doi.org/10.1134/s1062739148020116.

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9

Wang, Xufeng, Xuanlin Wang, Jiyao Wang, and Zhongxi Tian. "Feasibility Study and Prospects of Rock Fragmentation Using Ultrasonic Vibration Excitation." Applied Sciences 10, no. 17 (August 25, 2020): 5868. http://dx.doi.org/10.3390/app10175868.

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This paper systematically examines the feasibility of using ultrasonic vibration excitation for rock breakage and fragmentation; it focuses on the failure mechanisms of rock mass under the impact of ultrasonic waves, and the development of ultrasonic technology. Laboratory testing using a self-designed system was conducted in this paper to further validate the efficiency and reliability of rock breakage using ultrasonics. The results show that: (i) under the effects of both the high speed impact of ultrasonic vibration excitation and induced rock vibration excitation, a fracture is initiated and propagates rapidly within and outside of the rock. Under ultrasonic vibration excitation for 140 s, the compressive strength decreased by 45.6%; (ii) under the excitation of ultrasonics, the rock specimens failed completely in a short time from inside to outside, and there are distinct fissures in the internal nucleation of the rock. It is suggested that ultrasonic excitation provides a novel and promising option for rock fragmentation and breakage, which optimises the efficiency of underground hard rock engineering.

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Jiang, Hongxiang, Changlong Du, Songyong Liu, and Liping Wang. "Theoretical Modeling of Rock Breakage by Hydraulic and Mechanical Tool." Mathematical Problems in Engineering 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/895835.

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Rock breakage by coupled mechanical and hydraulic action has been developed over the past several decades, but theoretical study on rock fragmentation by mechanical tool with water pressure assistance was still lacking. The theoretical model of rock breakage by mechanical tool was developed based on the rock fracture mechanics and the solution of Boussinesq’s problem, and it could explain the process of rock fragmentation as well as predicating the peak reacting force. The theoretical model of rock breakage by coupled mechanical and hydraulic action was developed according to the superposition principle of intensity factors at the crack tip, and the reacting force of mechanical tool assisted by hydraulic action could be reduced obviously if the crack with a critical length could be produced by mechanical or hydraulic impact. The experimental results indicated that the peak reacting force could be reduced about 15% assisted by medium water pressure, and quick reduction of reacting force after peak value decreased the specific energy consumption of rock fragmentation by mechanical tool. The crack formation by mechanical or hydraulic impact was the prerequisite to improvement of the ability of combined breakage.

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Wang, Jiajun, Linqi Huang, Xibing Li, Yangchun Wu, and Huilin Liu. "Effect of Particle Size Distribution on the Dynamic Mechanical Properties and Fractal Characteristics of Cemented Rock Strata." Mathematics 10, no. 12 (June 15, 2022): 2078. http://dx.doi.org/10.3390/math10122078.

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To investigate the dynamic mechanics and post-failure characteristics of fault-cemented rock strata, broken rock particles were reshaped to obtain cemented rock samples with various particle size distributions (PSDs). Split Hopkinson pressure bar (SHPB) dynamic impact tests were performed on the cemented rock samples under different strain rates. The test results show that plastic deformation occurs in the cemented rock sample as a result of its porous structure. Therefore, there is no linear phase in the dynamic stress–strain curves. With an increase in the Talbot index and mixture type, more large particles were contained inside the cemented rock sample, and the dynamic strength gradually increased. A power function can effectively describe the relationship between the strain rate and dynamic strength for various Talbot indices. After dynamic impact, the fragments of the cemented rock samples exhibit evident fractal laws, and the breakage of the samples includes breakage of the original rock particle itself and breakage between the rock particles and cementations. The breakage ratio and fractal dimension both decrease with the increase in the number of mixture type and Talbot index but increase with the increase in strain rate. It is worth noting that the breakage ratio and fractal dimension have a linear relationship regardless of the PSD or strain. The relationship between the dynamic strength and fractal dimension has different response laws for the PSD and strain rate effects. The dynamic strength is negatively linearly related to the fractal dimension under the PSD effect but positively linearly related to the fractal dimension under the strain rate effect. This research work can provide foundation support for investigating the instability mechanism of fault cemented rock strata under dynamic stress.

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Wang, Jiyao, Xufeng Wang, Xuyang Chen, Liang Chen, Zhanbiao Yang, Zechao Chang, Lei Zhang, and Zhijun Niu. "Experimental Study on Failure Law and Mechanism of Red Sandstone under Ultrasonic Vibration Excitation." Geofluids 2022 (February 17, 2022): 1–13. http://dx.doi.org/10.1155/2022/3078599.

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Rock breakage is inevitable for creating openings in underground engineering operations. Ultrasonic vibration has been attracting extensive attention for such a practice considering its outstanding performance in rock breakage. In order to understand the fundamental failure mechanism of rocks subjected to ultrasonic vibrations, based on P-wave monitoring and the direct current electric method, we captured the evolution of the failure process of the red sandstone. In addition, we fundamentally analyse the failure mechanisms of the red sandstone using numerical simulation and microscopy scans. It was found that extensive fractures were initiated due to the ultrasonic vibration and the fractures propagated downwards forming a conical shape. The apparent resistivity became as high as 320000 Ω being 16 times the initial resistivity. The fracture propagated downwards as deep as 41 mm. The maximum damage parameter on the testing sample could be as high as 0.68, and it completely failed after 140 s of ultrasonic vibration duration. As a result of numerical simulation, it was found that the microfractures and pores in the testing sample were activated due to the stress wave resulting from the ultrasonic vibration leading to the fracture propagation and eventually complete failure. Through comparing the performance of uniaxial compressive loading and ultrasonic vibration techniques in rock damage, it was concluded the latter has a much higher capacity and competence in rock breakage.

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13

Li, Changping, Longchen Duan, Songcheng Tan, Victor Chikhotkin, and Wenpeng Fu. "Damage Model and Numerical Experiment of High-Voltage Electro Pulse Boring in Granite." Energies 12, no. 4 (February 22, 2019): 727. http://dx.doi.org/10.3390/en12040727.

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High-voltage electro pulse boring (EPB) has the advantages of high rock-breaking efficiency and good wall quality, and is a new and efficient potential method of rock breaking. The EPB process is defined as random because it is affected by many factors. At present, there is no suitable physical and mathematical model to describe the process and results of rock breakage in EPB, and the conclusions reached regarding rock-breakage mechanisms are not uniform. In this study, a complete damage model of high voltage EPB in granite is established, which includes a shock wave model and a damage model of high voltage EPB in granite. The damage model is based on the Particle Flow Code two-dimensional program. Use of a damage model of EPB accommodates the complete process of high voltage EPB, from discharge to production of a shock wave, and so rock-breaking via electro pulse can be simulated and calculated. The time-varying waveforms of shock waves with different electrical parameters are simulated and calculated on the basis of the model. Different shock wave forms are loaded into the surface and internal rock in the damage geometric model of EPB granite. Then, the breakage process of the rock surface and internally, and the mechanism of rock breakage using EPB are analyzed. This study provides a scientific basis for the quantitative expression and prediction of rock fragmentation in EPB in order to improve the drilling efficiency and reduction of energy loss in the process of EPB.

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14

Liu, Yang, Xiao Zhu Li, and Cheng Lin Wang. "Discrete Element Simulation of Rock Crushing Considering Different Shape." Applied Mechanics and Materials 353-356 (August 2013): 715–18. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.715.

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Numerical simulation was conducted to study the particle breakage of rock in rolling compaction (RC) test based on discrete element method (DEM). Different shapes of particles were formed to represent the real particle shape. A quantitative analysis method of particle breakage was proposed according to the grading curve before and after compaction. The numerical results had a good agrrement with the field test, which indicated that the method adopted in this paper was feasibile and could consider the influence of the particle shape on the particle breakage in RC test.

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Allemand, J., M. R. Shortis, and M. K. Elmouttie. "HIGH SPEED VIDEOMETRIC MONITORING OF ROCK BREAKAGE." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-2 (May 28, 2018): 17–24. http://dx.doi.org/10.5194/isprs-annals-iv-2-17-2018.

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Estimation of rock breakage characteristics plays an important role in optimising various industrial and mining processes used for rock comminution. Although little research has been undertaken into 3D photogrammetric measurement of the progeny kinematics, there is promising potential to improve the efficacy of rock breakage characterisation. In this study, the observation of progeny kinematics was conducted using a high speed, stereo videometric system based on laboratory experiments with a drop weight impact testing system. By manually tracking individual progeny through the captured video sequences, observed progeny coordinates can be used to determine 3D trajectories and velocities, supporting the idea that high speed video can be used for rock breakage characterisation purposes. An analysis of the results showed that the high speed videometric system successfully observed progeny trajectories and showed clear projection of the progeny away from the impact location. Velocities of the progeny could also be determined based on the trajectories and the video frame rate. These results were obtained despite the limitations of the photogrammetric system and experiment processes observed in this study. Accordingly there is sufficient evidence to conclude that high speed videometric systems are capable of observing progeny kinematics from drop weight impact tests. With further optimisation of the systems and processes used, there is potential for improving the efficacy of rock breakage characterisation from measurements with high speed videometric systems.

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Zheng, Lujing, Lulin Zheng, Yujun Zuo, Hao Liu, Bin Chen, Zhonghu Wu, Wenjibin Sun, and Yingle Wang. "Study on Mesoscale Damage Evolution Characteristics of Irregular Sandstone Particles Based on Digital Images and Fractal Theory." Advances in Materials Science and Engineering 2021 (November 27, 2021): 1–14. http://dx.doi.org/10.1155/2021/6552847.

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To study the mesoscale damage evolution law of irregular sandstone particles, based on RFPA2D and digital image processing technology, a real mesostructure numerical model of irregular sandstone particles is established to simulate the breakage process of particles, the effects of loading conditions and mesoscale heterogeneity on irregular sandstone particle damage are studied, and the calculation method of fractal dimension of irregular rock particles mesoscale fracture is proposed. The results show that the fracture damage degree (ω) and fractal dimension (D) maximum values of the constrained particles are 0.733 and 1.466, respectively, and the unconstrained particles are 0.577 and 1.153, respectively. The final failure mode of constrained particles is more complicated than unconstrained particles, the damage is more serious, and the fracture is more complete. Thus, the larger values of D yield a more complicated final failure mode of the particles. Consequently, with the larger ω, the final damage is more serious, and the breakage effect is comparatively better. The study is of great significance for exploring the laws of rock particle breakage and energy consumption, rock breakage mechanism, and searching for efficient and energy-saving rock-breaking methods.

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Monjezi, Masoud, Zabiholla Ahmadi, and Manoj Khandelwal. "Application of neural networks for the prediction of rock fragmentation in Chadormalu iron mine / Zastosowanie sieci neuronowych do prognozowania stopnia rozdrobnienia skał w kopalni rud żelaza w Chadormalu." Archives of Mining Sciences 57, no. 3 (December 1, 2012): 787–98. http://dx.doi.org/10.2478/v10267-012-0051-0.

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Abstract Most open-pit mining operations employ blasting for primary breakage of the in-situ rock mass. Inappropriate blasting techniques can result in excessive damage to the wall rock, decreasing stability and increasing water influx. In addition, it will result in either over and/or under breakage of rocks. The presence of over broken rocks can result in decreased wall stability and require additional excavation. In contrast, the presence of under broken rocks may require secondary blasting and additional crushing. Since blasting is a major cost factor, both cases (under and over breakage) create additional costs reflected in the increase of the operation and maintenance of the machinery. Quick and accurate measurements of fragment size distribution are essential for managing fragmented rock and other materials. Various fragmentation measurement techniques are available and are being used by industry/researchers but most of the methods are time consuming and not precise. An ideally performed blasting operation enormously influences the overall mining cost. This aim can be achieved by proper prediction and attenuation of fragmentation. Prediction of fragmentation is essential for optimizing blasting operation. Poor performance of the empirical models for predicting fragmentation has urged the application of new approaches. In this paper, artificial neural network (ANN) method is implemented to develop a model to predict rock fragmentation size distribution due to blasting in Chadormalu iron mine, Iran. In the development of the proposed ANN model, ten parameters such as UCS, drilling rate, water content, burden, spacing, stemming, hole diameter, bench height, powder factor and charge per delay were incorporated. Training and testing of the model was performed by the back-propagation algorithm using 97 datasets. A four-layer ANN was found to be optimum with architecture of 10-7-5-1. A comparison has made between measured results of fragmentation with predicted results of fragmentation by ANN and multiple regression model. Sensitivity analysis was also performed to understand the effect of each influencing parameters on rock fragmentation.

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Shi, Da Kun, and Yang Song Zhang. "A Study on Stability of Expressway Tunnel Surrounding Rock Containing Weak Intercalated Rock." Advanced Materials Research 168-170 (December 2010): 2543–47. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.2543.

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Weak intercalated rock plays an important role in the stability of engineering rock mass. It controls the mechanism of deformation and breakage of rocks. Systematic numerical tests have been carried out to study the stability of surrounding rock mass with different distributions of weak intercalated rock has been analyzed by the FEM software ABAQUS. All of the numerical modelings are plain-strain type with elasto-plastic constitutive law and Drucker-Prager failure criterion. Some quantificational results about the influence of weak intercalated rock are summarized, especially the influence on the deformation, stress of surrounding rocks and plastic zone. Because of weak intercalated rock, the stress of surrounding rock appears the character of discontinuity. In addition, the distribution of plastic zone is also affected. When weak intercalated rocks exist in vault, spandrel and bottom, the situation of surrounding rock is comparatively unfavorable. These results have a certain role in guiding significance to the site selection and layout, the majorization of supporting system and the construction of tunnel of the same kind.

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Si, Hu, Xiao Hong Li, and Yan Ming Xie. "Damage Analysis and Simulation of Rock under High Pressure Waterjet." Key Engineering Materials 462-463 (January 2011): 774–79. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.774.

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The high pressure waterjet is widely applied for mine industry, mechanical manufacture, environmental engineering, and medicine field due to its particular characteristic. Recently, the application of high pressure waterjet for gas drainage in mine has been receiving increasing attention with the development of exploitative technology. The micro-damage mechanism of coal under high pressure water jet is key to drain gas effectively. Based on damage mechanics and rock dynamics, the paper analyzed the micro-structure deformation and damage of rock and the impulsive effect under high pressure water jet and developed the dynamic model. Further, on the assumption of that rock was homogeneous and isotropic, a computational model was established based on the Arbitrary Lagrangian Eulerian (ALE) fluid-solid coupling penalty function method. The rock damage under high pressure water jet was simulated by the dynamic contact method. The results showed that the damage and breakage of ruck was mainly attributed to impacting effect and was characterized by local effect, and the evolvement of rock breakage went through three stages and the figure of rock breakage trended a funnel. On the whole, numerical results agreed with experimental results.

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Sui, Haoyue, Tianming Su, Ruilin Hu, Ke Yang, and Yaxing Cheng. "Liquid CO2 Phase-Transition Rock Fracturing: A Novel Technology for Safe Rock Excavation." Applied Sciences 12, no. 1 (December 22, 2021): 68. http://dx.doi.org/10.3390/app12010068.

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In order to determine the applicability of liquid CO2 phase-transition fracturing technology in rock mass excavations, the principles of CO2 phase-transition fracturing were analyzed, and field tests of liquid CO2 phase-transition fracturing were performed. An “Unmanned Aerial Vehicle (UAV) camera shooting + Microstructure Image Processing System (MIPS) analyzing” method was used to acquire the rock mass characteristics. Further, the Hilbert–Huang Transform (HHT) energy analysis principle was adopted to analyze the characteristics of fracturing vibration waves. The experimental results showed that during the process of fracturing, there were both dynamic actions of rock breakage due to excitation stress wave impacts, and quasi-static actions of rock breakage caused by gasification expansion wedges. In semi-infinite spaces, rock-breakage zones can mainly be divided into crushing zones, fracture zones, and vibration zones. At the same time, under ideal fracturing effects and large volumes, the fracturing granularity will be in accordance with the fractal laws. For example, the larger the fractal dimensions, the higher the proportion of small fragments, and vice versa. Moreover, the vibration waves of the liquid CO2 phase-transition fracturing have short durations, fast attenuation, and fewer high-frequency components. The dominant frequency band of energy will range between 0 and 20 Hz. The liquid CO2 phase-transition fracturing technology has been observed to overcome the shortcomings of traditional explosive blasting methods and can be applied to a variety of rock types. It is a safe and efficient method for rock-breaking excavations; therefore, the above technology effectively provides a new method for the follow-up of similar engineering practices.

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Huang, Ping Lu, and Cong Xin Chen. "Study on Stability of Consequent Rock Slope by Simulation Experiment." Advanced Materials Research 261-263 (May 2011): 1470–74. http://dx.doi.org/10.4028/www.scientific.net/amr.261-263.1470.

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Based on similarity theory, the geologic mechanics model is established and to be used for studying distortion and breakage mechanism of consequent rock slope. The paper introduces the design and process of the experimentation. Through experimentation of a slope model, the stability of a slope is studied. After analyzing the phenomenon and data of the experimentation, it is found that the major deformation model is slippage. The mode of breakage is sliding and fracturing. The process of slippage is graded. The more hinder the position of coast is, the smaller the obliquity of rip face is. The deformation and breakage of bedding slope firstly arises at the dig face near the earth's surface.

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Zhang, Yong Bo. "Experimental Research on Instability Activation Mechanism of Old Goaf Overburden Rock." Advanced Materials Research 250-253 (May 2011): 1426–32. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1426.

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Taking the 2204 working face of Xinzhi Colliery in Huozhou as the background, through experiment of analog simulation, analyze the structure type of old goaf overburden rock breakage, instability activation mechanism of overburden rock and instability form and condition for stability of voussoir beam of old goaf. As the result, after mining and breakage, the rock mass structure of old goaf and overburden rock can be divided four types. This secondary rock structure has an important effect on old goaf activation. The existence form will decide the basic characteristic of old goaf activation. Through the mechanics analysis on voussoir beam of old goaf , it is obtained that instability due to sliding mainly depend upon the physical mechanics characteristic of key block and sideward rock, W/T value, and additional load of building on surface and so on. Rotational instability is related to the physical mechanics characteristic of key block and sideward rock and thick and length ratio h/l of the hanging rock

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Gehle, C., and H. K. Kutter. "Breakage and shear behaviour of intermittent rock joints." International Journal of Rock Mechanics and Mining Sciences 40, no. 5 (July 2003): 687–700. http://dx.doi.org/10.1016/s1365-1609(03)00060-1.

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Gates, D. J., and M. Westcott. "Generating a rock breakage process from sieve data." Minerals Engineering 13, no. 14-15 (December 2000): 1603–14. http://dx.doi.org/10.1016/s0892-6875(00)00143-6.

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Gong, Qiuming, Xiuli Du, Zhen Li, and Qixin Wang. "Development of a mechanical rock breakage experimental platform." Tunnelling and Underground Space Technology 57 (August 2016): 129–36. http://dx.doi.org/10.1016/j.tust.2016.02.019.

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Haghighi, Rahim, Robert R. Britton, and Duane Skidmore. "Modelling gas pressure effects on explosive rock breakage." International Journal of Mining and Geological Engineering 6, no. 1 (March 1988): 73–79. http://dx.doi.org/10.1007/bf00881028.

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Kawatra, S. K., S. A. Moffat, T. C. Eisele, and K. A. DeLa’o. "The effects of freezing conditions on rock breakage." Mining, Metallurgy & Exploration 11, no. 3 (August 1994): 178–84. http://dx.doi.org/10.1007/bf03403060.

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Adhikary, Deepak P., Marc Elmouttie, Vincent Lemiale, and Brett Poulsen. "Recent advances in the stability assessment of natural and engineered rock slopes." Journal of Nepal Geological Society 50, no. 1 (December 21, 2016): 65–72. http://dx.doi.org/10.3126/jngs.v50i1.22866.

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Science’s understanding of the failure mechanisms of large natural and engineered slopes has been improved considerably over the past 15 years. Significant improvements have been realized in innovative methods of data acquisition through field measurement and monitoring, as well as numerical modelling techniques. However, inadequate understanding of complex geology and landslide processes means that any interpretation of landslide data remains mostly subjective. This causes major uncertainty in landslide risk assessment. Over the past decade, Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO; http://www.csiro.au/) has developed novel techniques to facilitate efficient assessment of rock slope stability. These include SirovisionTM, Siromodel, and three CSIRO numerical codes: CSIRO‑SPH, CSIRO‑DEM and CSIRO‑COSFLOW. SirovisionTM is a geological/geotechnical mapping and analysis system that generates accurate, scaled 3D images of rock faces from stereo photographs of exposed rock surfaces, allowing for rapid rock mass structural mapping. Siromodel is a polyhedral modelling system that reads the SirovisionTM data, generates discrete fracture networks (DFN) and performs polyhedral (rock block) modelling and a first‑pass stability analysis. CSIRO‑SPH, CSIRO‑DEM and CSIRO‑COSFLOW are all used for detailed stress‑deformation analysis of rock slopes; however, each code has its own problem‑specific advantage. CSIRO‑SPH is suited for large deformation problems, and can simulate large scale fluid flow problems, such as modelling a dam breakage. CSIRO‑DEM is suited for rock breakage process analysis, and assessment of the runout distance of failure debris. CSIRO‑COSFLOW is designed specifically for efficient, accurate stress‑deformation analysis of stability of structures on bedded sedimentary rocks, where failures along the preexisting bedding planes and through the intact rock layers occur simultaneously.

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Slashchov, Ihor. "Estimation of fracture systems parameters in rock massif by the finite element method." E3S Web of Conferences 109 (2019): 00094. http://dx.doi.org/10.1051/e3sconf/201910900094.

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Results of analytical, laboratory and mine studies of parameters of disintegration zones in structurally-heterogeneous rocks and fracture systems around of the deep mine roadways are presented. A mathematical model is proposed, which is realized with the help of the procedures of simulation modeling by finite element method. Based on the calculation of possible directions of the rock shearing (the “rock shear sites”) and breakage of bonds between the elements, the model allows determining orientation of dominant master fracture system development with taking into account natural structural defects in the rock massif. A new algorithm was created for determining master cracks and boundaries of disintegration zones with the layered rock, which differs by determining directions of rock shear sites in the elastoplastic problem considering residual strength and main structural defects of the structurally-heterogeneous rock massif. Regularities of organization of unidirectional rock shear sites and their distribution under the influence of mining operations in zones with inelastic deformations were established.

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Wang, Tao, Sihong Liu, Yan Feng, and Jidu Yu. "Compaction Characteristics and Minimum Void Ratio Prediction Model for Gap-Graded Soil-Rock Mixture." Applied Sciences 8, no. 12 (December 12, 2018): 2584. http://dx.doi.org/10.3390/app8122584.

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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.

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Yang, Xiaofeng, Hongliang Zhu, Xin Zhou, and Aiguo Nie. "Experimental investigation on the evolution of structure and mechanical properties of basalt induced by microwave irradiation." RSC Advances 10, no. 54 (2020): 32723–29. http://dx.doi.org/10.1039/d0ra04802j.

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Zhang, Zong-Xian, and Finn Ouchterlony. "Energy Requirement for Rock Breakage in Laboratory Experiments and Engineering Operations: A Review." Rock Mechanics and Rock Engineering 55, no. 2 (October 30, 2021): 629–67. http://dx.doi.org/10.1007/s00603-021-02687-6.

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AbstractBased on the review of a wide range of literature, this paper finds that: (1) the average specific surface energy of various single crystals is only 0.8 J/m2. (2) The average specific fracture energy of the rocks with a pre-crack under static cleavage tests is 4.6 J/m2. (3) The average specific fracture energy of the rocks with a pre-cut notch but with no pre-crack under static tensile fracture (mode I) tests is 4.6 J/m2. (4) The average specific fracture energies of regular rock specimens with neither pre-made crack nor pre-cut notch are 26.6, 13.9 and 25.7 J/m2 under uniaxial compression, tension and shear tests, respectively. (5) The average specific fracture energy of irregular single quartz particles under uniaxial compression is 13.8 J/m2. (6) The average specific fracture energy of particle beds under drop weight tests is 74.0 J/m2. (7) The average specific fracture energy of multi-particles in milling tests is 72.5 J/m2. (8) The average specific energy of rocks in percussive drilling is 399 J/m3, that in full-scale cutting is 131 J/m3, and that in rotary drilling is 157 J/m3. (9) The average energy efficiency of milling is only 1.10%. (10) The accurate measurements of specific fracture energy in blasting are too few to draw reliable conclusions. In the last part of the paper, the effects of inter-granular displacement, loading rate, confining pressure, surface area measurement, premade crack, attrition and thermal energy on the specific fracture energy of rock are discussed.

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Ma, Shuangwen, Chen Cao, and Qianjia Hui. "Main Roof Breakage and Vibration Induced Coal Burst Occurring in Longwall Roadways." Shock and Vibration 2021 (October 26, 2021): 1–7. http://dx.doi.org/10.1155/2021/4982522.

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Rock burst is one major threat to mining safety and economy. Rock burst occurring in the longwall mining roadway accounts for 85% of the total amount of burst events. This paper investigates the causality mechanism of rock burst in longwall roadways by establishing a finite elastic beam model in the working face based on the elastic foundation theory. The breakage process of the main roof and related dynamic effects are analysed. The result shows that the movement of the main roof shows free vibration under certain damping resistance. It is also found that the roof dominant vibration frequency increases with the increase in the thickness and elastic modulus of the roof. During roof vibration, the vertical stress applied on the coal mass is unloaded. The destressing of the roof-coal interface causes the coal mass in the roadway rib to slip into the roadway under the horizontal ground stress, resulting in rock burst. The possibility of rock burst increases with increase in the strength and thickness of the roof and horizontal ground stress within the coal mass. This mechanism explains the occurrence of rock burst in the mining roadway; it provides the fundamental theory for the prevention and controlling technologies of longwall roadway rock burst.

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He, Jiang, Lin-ming Dou, An-ye Cao, Si-yuan Gong, and Jian-wei Lü. "Rock burst induced by roof breakage and its prevention." Journal of Central South University 19, no. 4 (March 29, 2012): 1086–91. http://dx.doi.org/10.1007/s11771-012-1113-3.

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Bonfils, Benjamin, Grant R. Ballantyne, and Malcolm S. Powell. "Developments in incremental rock breakage testing methodologies and modelling." International Journal of Mineral Processing 152 (July 2016): 16–25. http://dx.doi.org/10.1016/j.minpro.2016.04.010.

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Ge, Zhao Long, Yi Yu Lu, Ji Ren Tang, Ke Hu, and Wen Feng Zhang. "Experimental Study of Mechanism of Rock Breakage with High-Pressure Cavitating Water Jets." Advanced Materials Research 243-249 (May 2011): 2130–37. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.2130.

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To explore the relationship among the erosion ability of high-pressure cavitating water jets, hydraulic parameters and rock nature with a series of experiments relating to the efficiency of rock-breaking with cavitating water jets for different porosity of rock under different confining pressures and pump pressures. The results show that the erosion efficiency (erosion mass and erosion depth) of cavitating water jets is fitted a conic curve with pump pressure and confining pressure. It increases with the pump pressure increases while decreases with the confining pressure increases; the length of the bubble cloud decreases with the confining pressure increase and the length increases with the pump pressure increase, which is accorded with cubic curve. The bubble cloud length influences the rock-breaking efficiency by deciding the valid stand-off distance directly. Under the experimental condition, the cavitation happens once the pump pressure reaches 7MPa, and the cavitating water jets can crushing the sandstones which the uniaxial compressive strength is 96MPa. On the other hand, the porosity of rock is another main factor of rock breakage with high pressure cavitating water jets. The higher the porosity of rock is, the easier the rock can be broken.

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Yang, Li Jun, Wen Hui Bai, Bin Xiang Sun, Shuang Jie Wang, and Jin Zhao Zhang. "Effect of Vibrating Load on Grain Size Distribution of Crushed Rock Layer." Advanced Materials Research 168-170 (December 2010): 663–68. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.663.

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For the construction of the proposed Qinghai-Tibet Express Highway in warm and ice-rich permafrost regions, it will be necessary to utilize the new technique of cooling the ground temperature by the coarsely crushed rock layer with a low fines content, instead of the traditional measures taken to increase simply thermal resistances, so as to protect from damage to highway embankment due to thaw settlement. The vibrating loads such as wheel load and tamping load may cause the breakage and abrasion of the matrix grains in the coarsely crushed rock layer. This results in decreasing of grain size and increasing of fines content in the crushed rock layer, thus decreasing the porosity of crushed rock layer. The smaller porosity of crushed rock layer may weaken the cooling effect of buoyancy-driven natural convection of the pore air in the crushed rock layer of the highway embankment, thus resulting in instability and failure of the embankment structure in permafrost regions. Under these conditions, the influence of vibrating load on the grain size distribution of the coarsely crushed rock layer has to be investigated experimentally. In the present study, laboratory experiments on the grain size variation of the coarsely crushed rock layer under vertically vibrating loads were carried out. The test results show that the vibrating load can cause the breakage and abrasion of the matrix grains in the coarsely crushed rock layer and the shapes of coarely crushed rock grain tend to be non-angular.

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Wang, Jun, Jingxuan Yang, Fengfeng Wu, Tengfei Hu, and Shams Al Faisal. "Analysis of fracture mechanism for surrounding rock hole based on water-filled blasting." International Journal of Coal Science & Technology 7, no. 4 (June 2, 2020): 704–13. http://dx.doi.org/10.1007/s40789-020-00327-y.

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AbstractThe principles of fracture development during underwater blasting are examined based on explosion and impact dynamics, fluid dynamics, fracture dynamics, and field testing. The research reveals that the fracturing of the surrounding rock during underwater blasting is due to the combined action of shock and stress waves for the initial rock breakage and subsequent water expansion. The fracture development model for the surrounding rock of a drilling hole during underwater blasting is established. The rock fracturing range under the combined action of shock and stress waves is developed, as well as the fracture propagation rules after the wedging of the water medium into the fractures. Finally, the results of deep-hole underwater blasting tests on large rocks confirm the efficient utilization of explosive in the hole to improve the safety conditions. Accordingly, safe and static rock breaking under the detonation of high-effect explosive can be achieved. In addition, super-dynamic loading from the explosions and static loading from the water medium in the hole can be adequately combined for rock breaking.

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Gómez, R., R. Castro, F. Betancourt, and M. Moncada. "Comparison of normalized and non-normalized block caving comminution models." Journal of the Southern African Institute of Mining and Metallurgy 121, no. 11 (November 30, 2021): 1–8. http://dx.doi.org/10.17159/2411-9717/1150/2021.

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In block cave mining, rock fragmentation is a key parameter that influences the production level design and mine planning. Fragmentation occurs mainly by natural breakage during the caving process and in the draw column. The breakage that occurs within the column is known as secondary fragmentation. Secondary fragmentation has been successfully described using the block caving comminution model, which replicates the fragmentation mechanics between particles under drawn and vertical loads in a draw column. This model is based on a kinetic and population balance approach, in which non-normalized and normalized assumptions can be used depending on material and comminution system behaviour. In this paper, the non-normalized and normalized approaches are applied and compared to laboratory data to determine which assumption should be used for secondary breakage in block caving. Approaches are compared graphically, with the mean square error and the Fisher test with a false-rejection probability of 0.05. Based on a statistical analysis, the results show that the normalized model can be applied to all the rock types tested.

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Liu, Shuang, Qing Wen Ren, and Chen Lu Zhou. "Numerical Research on the Gravity Dam Deep Anti-Sliding with Engineering Mechanics Based on Damage Theory." Advanced Materials Research 910 (March 2014): 289–96. http://dx.doi.org/10.4028/www.scientific.net/amr.910.289.

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Currently, researches on the gravity dam deep and shallow anti-sliding stability mainly focus on the analysis method and instability criterion, while the studies on specifically test the breakage of gravity dams due to weakening foundation rock mass and structural planes under loading are rare. Based on damage mechanics theory, this paper established a numerical model that analyzed the damage failure process of dam foundation rock mass. Taking two typical gravity dam models as the study objects, the damage processes of the dam foundations were simulated dynamically. Additionally, a comparison with other two traditional methods further validated the correctness and feasibility of the numerical model. In sum, the study findings point out that the numerical model is not only applicable to the study of the breakage mechanism of dam foundation rock mass, but also can be used as a new method to analyze problems related to deep anti-sliding stability of gravity dams.

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41

Hood, M., G. C. Knight, and E. D. Thimons. "A Review of Jet Assisted Rock Cutting." Journal of Engineering for Industry 114, no. 2 (May 1, 1992): 196–206. http://dx.doi.org/10.1115/1.2899772.

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High volume, low pressure water jets have been employed for erosion of loosely consolidated rocks for centuries and this excavation method finds application in specialized circumstances even today. The use of high pressure, low volume water jets for rock cutting is more recent and was made possible by the development of high pressure water pumps. This approach to rock breakage has been touted by an enthusiastic group of research workers, and we count ourselves among these workers, for at least the past two decades. Despite the benefits often claimed for these systems, high pressure water jets still have not found widespread application. In this paper we review the various methods that have been employed using waterjets to break rock and we focus on one method, termed jet assisted cutting, which, in our view is the closest to commercial development. We review the current state of knowledge based on laboratory and field experiences using this cutting method and we assess possible future developments for this approach to excavation.

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42

Teimoori, Khashayar, and Richard Cooper. "Multiphysics study of microwave irradiation effects on rock breakage system." International Journal of Rock Mechanics and Mining Sciences 140 (April 2021): 104586. http://dx.doi.org/10.1016/j.ijrmms.2020.104586.

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43

Reddish, D. J., L. R. Stace, P. Vanichkobchinda, and D. N. Whittles. "Numerical simulation of the dynamic impact breakage testing of rock." International Journal of Rock Mechanics and Mining Sciences 42, no. 2 (February 2005): 167–76. http://dx.doi.org/10.1016/j.ijrmms.2004.06.004.

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44

Haghighi, R., R. R. Britton, and D. Skidmore. "Modelling gas pressure effects on explosive rock breakage: short communication." International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts 26, no. 2 (March 1989): 77. http://dx.doi.org/10.1016/0148-9062(89)90217-9.

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Satish, H., J. Ouellet, V. Raghavan, and P. Radziszewski. "Investigating microwave assisted rock breakage for possible space mining applications." Mining Technology 115, no. 1 (March 2006): 34–40. http://dx.doi.org/10.1179/174328606x101902.

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Briggs, C. A., and R. A. Bearman. "An investigation of rock breakage and damage in comminution equipment." Minerals Engineering 9, no. 5 (May 1996): 489–97. http://dx.doi.org/10.1016/0892-6875(96)00037-4.

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47

Wang, Peng, Zhina Li, Hongjian Ni, Yuandong Liu, and Peng Dou. "Experimental study of rock breakage of an interrupted pulsed waterjet." Energy Reports 6 (November 2020): 713–20. http://dx.doi.org/10.1016/j.egyr.2020.03.018.

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48

Wang, Xiao-Bo, Wen-Jie Xu, Bing-Yin Zhang, and Qi-Cheng Sun. "Particle crushing simulations with improved discontinuous deformation analysis." Engineering Computations 31, no. 7 (September 30, 2014): 1321–41. http://dx.doi.org/10.1108/ec-02-2013-0051.

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Purpose – Rock-fill dams are embankments of compacted free-draining granular earth containing an impervious zone. Earth utilized in such dams often contains a high percentage of large particles – hence the term rock-fill. Mass stability of these dams results from friction and particle interactions rather than through a cementing agent binding the particles together. However, high-stress conditions and prolonged exposure to the elements can severely damage rock-fill. Therefore, understanding and modeling rock-fill breakage is important for dam engineering. The purpose of this paper is to improve discontinuous deformation analysis (DDA) techniques for modeling rock-fill breakage, proving the new method using simulations of spherical particle crushing. Design/methodology/approach – This work models rock-fill as bonded ellipsoid particles, and develops an improved DDA method to model the breakage of particle assemblies. The paper starts by describing the principles of three-dimensional DDA for spherical particles, and then derives the submatrices for normal contact, shear contact, and frictional force. The new algorithm incorporates a bond model with a revised open-close iteration algorithm into the DDA method to simulate particle crushing. To validate the improved DDA method, calculated particle contacts and movements are validated against theoretical results. Finally, this work performs a series of point-loading experimental tests for cement ellipsoid particles of both high and low compression strengths, with the test results compared against the results from corresponding DDA simulations. Findings – In particle crushing tests, the force and displacement show an approximately linear relationship until the crushing point, at which point low compression ellipsoid particles split into several large pieces while the high-compression particles break into many small fragments. The DDA simulation results are in good agreement with the crushing tests, demonstrating the validity of the DDA method for solving particle crushing problems. Although the improved DDA model is applicable to rock-fill particle crushing studies, some issues remain, particularly in increasing calculation efficiency and performing large-scale computations and long real-time simulations. Future research should address these issues. Originality/value – A bond model with a revised open-close iteration algorithm is incorporated into the DDA method. The simulated results shed insight into rock-fill crushing mechanisms, an element of concern in engineering practices.

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Spreafico, Margherita C., Francesca Franci, Gabriele Bitelli, Lisa Borgatti, and Monica Ghirotti. "Intact rock bridge breakage and rock mass fragmentation upon failure: quantification using remote sensing techniques." Photogrammetric Record 32, no. 160 (December 2017): 513–36. http://dx.doi.org/10.1111/phor.12225.

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Qiao, Deng Pan, Ya Ning Sun, Shu Hong Wang, and Juan Xia Zhang. "Numerical Simulation on Cracks Propagation and Coalescence Process in Rock." Key Engineering Materials 353-358 (September 2007): 933–36. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.933.

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The failure of rock mass under loading is resulting from preexisting flaws, such as cracks, pores and other defects. However, the propagation and coalescence mechanism among multi-group cracks is still a puzzle, especially to the engineering rocks in site. In this study, the failure of rock samples with two groups of preexisting parallel cracks under the axial load were numerically investigated by the Rock Failure Process Analysis code (RFPA) from a mechanics point of view. The simulated results reproduce the rock failure process: at the first loading stage, the particle is stressed and energy is stored as elastic strain energy with a few randomly isolated fractures. As the load increases, the isolated fractures are localized to form a macroscopic crack. At the peak load, the isolated fractures unstably propagate in a direction parallel to the loading direction following tortuous paths and with numerous crack branches. Finally, the major crack passes through the rock sample and several coarse progeny cracks are formed. Moreover, in the vicinity of the contacting zone the local crushing is always induced to cause fines. On the base of the simulated results, it is found that the dominant breakage mechanisms are catastrophic splitting and progressive crushing. It is pointed out that the particle breakage behavior strongly depends on the heterogeneous material property, the irregular shape and size, and the various loading conditions. Because of heterogeneity, the crack propagates in tortuous path and crack branching becomes a usual phenomenon. The failure process of rock sample demonstrated that due to the high stress concentration at the cracks tip or some weaker strength elements which are not on the cracks surface initiate some micro-fractures, those cracks and fractures may gradually become larger and larger, more and more with the progress of loading so that join into the branch cracks leading to the rock failure in the end. Not only did the output of the numerical simulation study compare well with the experiment results, but also the further insights of the mechanism of cracks propagation and coalescence process in rock mass were obtained.

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Journal articles on the topic 'Rock breakage'

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