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1
Ye, Dayu, Guannan Liu, Ning Luo, Feng Gao, Xinmin Zhu, and Fengtian Yue. "Quantitative Analysis of the Topological Structure of Rock Pore Network." Geofluids 2021 (June 13, 2021): 1–11. http://dx.doi.org/10.1155/2021/5517489.
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As the most significant nonlinear reservoir, the rocks have complex structural characteristic. The pore structure of the rock is varied in shape and complex in connectivity. However, the prevailing methods for characterising the microstructure of rocks, such as the coordination number method and fractal theory, are still difficult to quantify the structural properties. In this study, based on the CT-scan method and a new complex network theory, the topological characteristics of rocks such as seepage path selection, degree of pore aggregation, pore importance, and pore module structure are analysed. The results show that the scale-free network model is more reliable in characterising the rock pore network than previously published structural models, and a small number of pores are the “key” to the seepage process. Besides, we proposed a new method to quantify the importance of rock pores and present the distribution characteristics and connectivity laws of the rock-pore network. This provides a new method to study the seepage process of the nonlinear reservoirs.
2
Xiao, Xiao Ling, and Xiang Zhang. "Structure Analysis of Volcanic Rock Based on the Texture Feature in Imaging Logging." Advanced Materials Research 915-916 (April 2014): 1229–33. http://dx.doi.org/10.4028/www.scientific.net/amr.915-916.1229.
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The rock structure information is a very important feature in the complex lithology identification. However, conventional logging response characteristics of the rock structures are very weaker, resulting that the recognition rate of complex lithology is very low in conventional logging. With the help of imaging logging data with accurate, intuitive structural characteristics of the rock, the volcanic structure is analyzed in electronic imaging logging data in this paper. First, several structural characteristics of volcanic rock are introduced. Then, several texture features are extracted based on image processing method. Finally, imaging logging response characteristics of different volcanic structures are analyzed by means of histogram, and some texture features of imaging logging are chosen to identify volcanic structures in the cross-plot method. Real data processing analysis results show that texture features extracted from electrical imaging logging is effective to distinguish the structures of volcanic rocks.
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Ekvist, B. V., and N. G. Barnov. "Explosive Fragmentation of Rock Masses with Heterogeneous Structure." Mining Industry Journal (Gornay Promishlennost), no. 3/2021 (July 20, 2021): 135–38. http://dx.doi.org/10.30686/1609-9192-2021-3-135-138.
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A method to optimize drilling and blasting parameters with account of the physical and technical properties of rocks within the blasted block is proposed to improve the quality of blasting in open pit mines characterized by complex geological settings. The results of laboratory tests are provided that confirm improvement in the quality of rock sample crushing by blasting charges with variable delays and locations, depending on the strength properties of the samples, relative to blasting charges with unchanged parameters. The proposed method can be used in combination with GPR surveys of the rock mass. Explosive fragmentation of the rock masses with complex structures is characterized with a number of features caused by changes in the strength properties within the blasted block. In order to optimize the fragmentation efficiency of rock masses with complex geological structure, it is required to assess physical and technical properties of rocks and to determine their location and variations of the strength properties within the blasted block. It is possible to quickly assess the physical and technical properties of the blasted rocks using the surface georadar method. The outcome of this method is georeferencing of the reoradar data to the location and properties of the rocks to be blasted, along with the methodology of applying the georadar surveys, selection of the areal assembly type depending on the size and properties of detected jointing, and economic justification of applying this method. The novelty consists in linking the georadar data on the rocks to be blasted with drilling and blasting parameters.
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Wang, Yafei, Zhanrong Zhang, Xingpei Kang, Hao Xie, Chenchen Wang, and Kun Liu. "Stability Analysis of Soil and Rock Mixed Slope Based on Random Heterogeneous Structure." Advances in Civil Engineering 2024 (February 19, 2024): 1–12. http://dx.doi.org/10.1155/2024/1448371.
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Due to the complexity in the heterogeneous internal structure and interactions between rocks and soil, the slide of soil–rock mixed slope is usually more complex than that of a homogeneous soil slope. This paper investigated the stability of soil–rock mixed slopes with finite element method (FEM) based on random heterogeneous structure. An image-aided approach was used to generate the 2-D and 3-D digital rocks to ensure the morphology of digital rocks was similar with the real rocks. The 2-D and 3-D soil–rock mixed slopes were then generated by placing the digital rocks into the soil matrix. The generated heterogeneous structures of soil–rock mixed slope were imported into ABAQUS for numerical analysis. The effect of rock content, spatial distributions, material properties, and rock–soil interface on the stability of soil–rock mixed slopes were analyzed. Results show that the stability factor of the soil–rock mixed slope increases with the increase of rock content. The rocks can play a certain degree of antislide effect in the slope. The uneven spatial distribution of rocks has effect on the overall stability of soil–rock mixed slope. This effect is more significant when the rock content is moderate. Rocks distributed in the middle layer of the slope may improve the overall antisliding performance of the slope. The stability factor decreases with the increase of rock density. While the effect of rock elastic modulus on stability of soil–rock mixed slope is relatively limited. The contact condition at the soil–rock interface has effect on the overall stability of soil–rock mixed slope. It is recommended to properly determine the interface properties for stability analysis of soil–rock mixed slope.
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Xiong, Ting, Ming Chen, Yuan Jin, et al. "A New Multi-Scale Method to Evaluate the Porosity and MICP Curve for Digital Rock of Complex Reservoir." Energies 16, no. 22 (2023): 7613. http://dx.doi.org/10.3390/en16227613.
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The evaluation of rock porosity and the mercury injection capillary pressure (MICP) curve is fundamental for oil and gas exploration and production. Digital rock (DR) technology, incorporating 3D micro-CT imaging and numerical methods, has been widely employed to predict these properties. However, analyzing the pore structure of heterogeneous rocks, such as fractured rocks or glutenite, solely through single-scale DR analysis poses challenges. Existing upscaling methods have limitations in fully representing the complete range of pore structures at different scales, with limited comparison to experimental data. To address this, we propose a novel method that upscales porosity and simulates the MICP curve from nano-scale to core scale by merging results from micro-CT (at resolutions of 35 μm and 2 μm) and SEM (at resolutions of 6.5 nm and 65 nm). We validate the developed DR model by applying it to sandstones, glutenite, and igneous rocks, and achieve excellent agreement between the experimental data and the multi-scale DR model across 67 samples. The results demonstrate that the multi-scale model effectively captures the porosity and pore structures across the entire range. In contrast, the single digital rock (DR) model underestimates the porosity measurements for both homogeneous sandstones and heterogeneous cores. While the MICP model based on a single DR proves suitable for homogeneous rock samples, it introduces noticeable discrepancies when applied to heterogeneous rock samples. The developed multi-scale method significantly enhances the confidence in using DR to assess the pore structure of complex rocks.
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Gu, Wenbin, Zhenxiong Wang, Jianghai Chen, Jianqing Liu, and Ming Lu. "Experimental and Theoretical Study on Influence of Different Charging Structures on Blasting Vibration Energy." Shock and Vibration 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/248739.
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As an important parameter in blasting design, charging structure directly influences blasting effect. Due to complex conditions of this blasting and excavating engineering in Jiangsu, China, the authors carried out comparative researches with coupling structure, air-decoupling structure, and water-decoupling structure. After collecting, comparing, and analyzing produced signals on blasting vibration, the authors summarized that when proportional distances are the same, water-decoupling structure can reduce instantaneous energy of blasting vibration more effectively with more average rock fragmentation and less harm of dust. From the perspective of impedance matching, the present paper analyzed influence of charging structure on blasting vibration energy, demonstrating that impedance matching relationship between explosive and rock changes because of different charging structures. Through deducing relationship equation that meets the impedance matching of explosive and rock under different charging structures, the research concludes that when blasting rocks with high impedance, explosive with high impedance can better transmits blasting energy. Besides, when employing decoupling charging, there exists a reasonable decoupling coefficient helping realize impedance matching of explosive and rock.
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Wang, Jian Hua. "Study on Random Reliability Analysis of Dam Abutment." Advanced Materials Research 214 (February 2011): 218–23. http://dx.doi.org/10.4028/www.scientific.net/amr.214.218.
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Stability reliability analysis of abutment rock of arch dam is a very complicated problem which must be studied and solved. Generally, entirely sliding stability reliability analysis should be made when abutment rock bounded by structure planes like fault, joints and fissures, and layers is possible to slide. Due to the complex causes and structures, diverse litholigy, different rocks have different mechanics attributes. While the physical and mechanical parameters of the same rocks are of obvious dispersion and uncertainty. And it is also complex to calculate the pushing force at arch abutment on dam abutment rock, because the uncertain factors as water pressure, sediment, variable temperatures and materials parameters are contained. In this essay, based on Stochastic Finite Element Method, the formula of sliding stability reliability analysis of dam abutment rock is given. The formula can be used for entirely stability reliability analysis of dam abutment.
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Zhang, Zhi Zeng, Jin Hu Zhang, Dong Qi Hou, and Xiao Peng Chen. "Displacement Analytic Solution of a Deep Elliptical Tunnel in Transversely Isotropic Rock Mass." Advanced Materials Research 402 (November 2011): 593–97. http://dx.doi.org/10.4028/www.scientific.net/amr.402.593.
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Sedimentary rocks with layered structure account for two third of global land area, and this proportion is 77.3% in China, lots of metamorphic rocks also have significant features of layered structure, so there are a large number of stability problems about layered rock mass in mining engineering. Layered rock mass is generally considered to be transversely isotropic solid in mechanics. Based on the complex variable expression of displacement components of transversely isotropy, the displacement analytical solution of a deep elliptical tunnel in transversely isotropic rock mass is derived by conformal mapping method.
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Marinos, P. V. "NEW PROPOSED GSI CLASSIFICATION CHARTS FOR WEAK OR COMPLEX ROCK MASSES." Bulletin of the Geological Society of Greece 43, no. 3 (2017): 1248. http://dx.doi.org/10.12681/bgsg.11301.
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The paper deals with the geotechnical classification of weak and complex rock masses. The complexity of these geological material demands a more specialized research and geological characterization due to the special features of their rock mass types regarding both their structure and their lithological characteristics. The weak and complex rock masses under consideration, often heterogeneous and containing rocks of extremely low strength, have in most cases undergone highly tectonised disturbance resulting in the destruction of their initial structure, while weathering can be another particular feature. The geotechnical types and their characterization of rock masses that can be developed in flysch, molasse, brecciated limestone, ophiolites and disturbed or weathered gneiss are studied here. In order to describe these masses in a quantitative way and provide numerical values to engineering design, new or revised rock mass classification diagrams are introduced within the general concept of the GSI system, or specific projections inside the existing GSI diagram are proposed The fundamental source for this research was data from the design and construction of 62 tunnels of Egnatia Highway appropriately assessed, processed, correlated and associated with field work.
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Lyashenko, Vasyl, Boris Andreev, and Tamara Dudar. "Substantiation of mining-technical and environmental safety of underground mining of complex-structure ore deposits." Mining of Mineral Deposits 16, no. 1 (2022): 43–51. http://dx.doi.org/10.33271/mining16.01.043.
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Purpose. Substantiation of mining-technical and environmental safety of underground mining of complex-structure ore deposits based on the study of a rock mass stress-strain state (SSS), as well as determining the safe parameters of stopes for specific mining-geological conditions and patterns of rock pressure propagation in various environments. Methods. To assess the improvement of mining-technical and environmental safety of mining operations, the research includes theoretical generalizations with the use of mathematical statistics, physical and mathematical modeling, performing calculations, as well as technical and economic feasibility, laboratory and full-scale experimental studies, industrial tests in mine conditions and on the earth's surface in the zone of blasting influence, based on the standard and new methods. Findings. A functional interrelation between the rock mass SSS value and the number of impulses (destruction sounds) per minute, characterizing its structural (а) and strength (b) properties, is proposed, which is described by a curvilinear dependence of the type y = axb and allows to quickly determine the stable parameters of stopes. Assessment and prediction are made for various forms of rock pressure manifestation, based on the stress concentration coefficient within 0.91 Kv 0.70, taking into account the conditions of the elastic behavior of rocks. The value of = 0.0002-0.0003 is taken as permissible relative deformation, which ensures both mining-technical and environmental safety, as well as the rock mass stability during repeated blasting operations. Originality. A classification of the rock mass SSS has been developed depending on the direction of the maximum stresses relative to the mine working location, the level of the rock mass stress state and the mechanism of rock pressure manifestation (η), as well as the category of rock-bump hazard. In particular, the rock mass with the values in the range oof 0.12 < η ≤0.2; 0.2 < η ≤ 0.3; 0.3 < η ≤ 0.5 and η > 0.5 are classified as non-rock-bump hazardous and belong to III, II, and I hazard categories, respectively. Practical implications. To substantiate the safe parameters of stopes based on the results of multi-year research into underground mining of complex-structure deposits, depending on the rock mass properties, a graphical-analytic method (nomographic charts and calculation formulas) is recommended. These parameters are determined for highly fractured, medium fractured and weakly fractured rock mass with its horizontal outcropping to the surface. Using this method, the Instruction on the Geomechanical Substantiation of the Safe Mining of the Reserves at the Skhidnyi Hirnycho-Zbahachuvalnyi Kombinat, DP (SE VostGOK), Ukraine, has been developed.
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Li, Mingchao, Yanqing Han, Gang Wang, and Fugen Yan. "3D Multiscale Integrated Modeling Approach of Complex Rock Mass Structures." Mathematical Problems in Engineering 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/867542.
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Based on abundant geological data of different regions and different scales in hydraulic engineering, a new approach of 3D engineering-scale and statistical-scale integrated modeling was put forward, considering the complex relationships among geological structures and discontinuities and hydraulic structures. For engineering-scale geological structures, the 3D rock mass model of the study region was built by the exact match modeling method and the reliability analysis technique. For statistical-scale jointed rock mass, the random network simulation modeling method was realized, including Baecher structure plane model, Monte Carlo simulation, and dynamic check of random discontinuities, and the corresponding software program was developed. Finally, the refined model was reconstructed integrating with the engineering-scale model of rock structures, the statistical-scale model of discontinuities network, and the hydraulic structures model. It has been applied to the practical hydraulic project and offers the model basis for the analysis of hydraulic rock mass structures.
12
Zhang, Qin Xiang, Hua Zhao, Ting Hui Xu, and Shi Ping Zhang. "Practice and Theoretical Thought on the Supporting for Soft Rock." Advanced Materials Research 535-537 (June 2012): 2032–36. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.2032.
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The support of soft rock roadway is the worldwide problem in Coal resources exploitation, and this problem affect production safety and efficiency of coal mining serious. The surrounding rock of Ronghua coal mine is complex soft rock with expansibility, complex geological structure and deep high stress, large deformation of rocks, floor heave serious , supporting difficulties, frequent overhaul, waste a lot of manpower and material resources, and serious threats to the mine's safety production. After many years of practicing, a new idea of supporting the soft rock in different time periods, which is” avoiding first, then resistance”, was propounded. Based on the lithology of surrounding rock and geologic structure, the roadway’s length of service, application, and service condition were considered, several pointed support schemes of roadway in -650m level: Super-strong supporting, High-strong supporting, Flexibility combined supporting and Retractable U-shaped supporting were confirmed. A whole soft rock supporting technology system has been formed which effectively solved the difficult problems of soft rock supporting. These achievements can provide useful experience for similar engineering problems.
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Kushnerov, Ivan, Serhii Fedorenko, and Ivan Maksymov. "Development of an efficient and safe technology for extracting horizontal and flat contiguous beds." IOP Conference Series: Earth and Environmental Science 1491, no. 1 (2025): 012024. https://doi.org/10.1088/1755-1315/1491/1/012024.
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Abstract Mine fields are very often represented by parallel contiguous horizontal, flat beds or complex-structured deposits of minerals with inclusions of waste rocks of various thickness. The work aims to develop a new technology and parameters for extracting horizontal and flat contiguous beds with efficient control of the surrounding rock state and reducing the cost of waste rock disposal during secondary development. The scientific novelty lies in developing an efficient and safe innovative technology for mining horizontal and flat contiguous beds of minerals. New dependencies of volumes of waste rock disposal on secondary development in artificial pillars-supports are established. The practical significance consists in expanding the scope of employment of the flowsheet for mining horizontal and flat contiguous beds including complex-structured deposits, increasing efficiency and safety of their extraction by creating a corrugated spatial structure to maintain the stable state of the surrounding rocks and the mining system elements. Implementation of the proposed technology enables reduction of the cost of extracting minerals from parallel horizontal and flat beds.
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Hou, Yuting, Die Liu, Taiping Zhao, et al. "Numerical Simulation of Electrical Properties of Carbonate Reservoirs Using Digital Rocks." Processes 11, no. 7 (2023): 2214. http://dx.doi.org/10.3390/pr11072214.
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Rock electrical experiments are essential means of researching the conductive properties of rocks and are fundamental to interpreting resistivity logging. Carbonate rocks have more complex pore structures than sandstone, which results in more complex conductive properties. However, conducting experiments on representative rock samples from carbonate reservoirs is difficult, making it challenging to study the micro factors affecting electrical properties. Therefore, researching the conductive properties of carbonate rocks is difficult. To address this, in this paper, three-dimensional (3D) digital rock models with different porosities are generated, and conductive simulations are carried out on these models using the finite element method (FEM). Firstly, a micro-computed tomography (μ-CT) 3D image of a carbonate rock is obtained. Secondly, mathematical morphology-based methods are used on the μ-CT image to generate cores with varying porosities and fluid distributions. Then, the electrical properties are simulated using the FEM method, and the results are analyzed. The results reveal that the formation factor of the reservoir is mainly influenced by the shape and structure of the pores. The Archie equation is more suitable for carbonate reservoirs with water saturation levels greater than 60%. The wettability of the rock can alter the distribution of fluid in the reservoir space under different water saturation conditions. In pure water-wet rocks, the water phase mainly occupies small pores, while the oil phase occupies larger pores. As a result, compared to pure oil-wet rocks, water-wet rocks have more conductive channels and better conductivity. Therefore, it is important to determine the wettability of the rock when calculating water saturation using the Archie equation. The saturation index value of water-wet carbonate rock is about 2, while that of oil-wet rock is around 3–4. This research lays a foundation for studying the electrical conductivity of carbonate reservoirs using digital rocks.
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Tian, Bo, Xuexiang Deng, Congwang Pan, and Xiangxi Meng. "An Investigation on the Pore Structure Characterization of Sandstone Using a Scanning Electron Microscope and an Online Nuclear Magnetic Resonance System." Applied Sciences 14, no. 16 (2024): 7063. http://dx.doi.org/10.3390/app14167063.
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The micropore structure of porous media (such as natural rocks and man-made materials) is very complex and has strong micro heterogeneity, and pore structure is a critical parameter to estimate the rock quality. However, the pore structure characterization of rocks under load is not studied well. In this paper, sandstone specimens were preloaded to six different stress levels, and then the pore structure of rock was characterized by SEM and NMR, respectively. The results show the following: (1) The damage in sandstone increases with predefined stress, and the rate significantly increases over 0.8 uniaxial compressive strength (UCS). (2) There is a critical value in the process of rock damage (0.8 UCS), and when it is less than this critical value, the microstructure in the rock is mainly composed of pores and micro-cracks, and the length is generally less than 5 μm; when it exceeds the critical value, there are obvious cracks or even groups of cracks inside the rock. (3) The changes in porosity can be divided into three stages, showing a “√” shape tendency. (4) The pore structure can be visually presented using NMR and SEM, and the distribution mode of the pores changes from separated points to concentrated patches to finally interconnected networks of pores with an increase in the predefined stress. Overall, NMR provides a new method for characterizing rock damage and studying rock microstructure.
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Babii, К. V. "INFLUENCE OF PARAMETERS OF EXPLOSIVE DESTRUCTION OF MINING BLOCKS OF COMPLEX GEOLOGICAL STRUCTURE ON THE PREPARATION OF THE MINING MASS FOR PROCESSING." Metallurgicheskaya i gornorudnaya promyshlennost, №6, 2018, no. 6 (2018): 68–74. http://dx.doi.org/10.33101/s065676567.
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Purpose: to investigate the influence of the parameters of explosive destruction of mining blocks of complex geological structure on the production processes of mining and processing of iron ore. Determine the stability of the escarpment slopes during excavation of rocks in ore mining blocks with barren layers. Results. The analysis of geophysical methods for studying the structure of deposits. It is proposed to use the magnetic susceptibility method for well logging. The structure of mining blocks of a complex geological structure with contact zones "ore - host rocks" was investigated. It has been proven that for the effective use of equipment for the pre-enrichment of ore in a quarry there are conditions: the regulation of the granulometric composition of the rock mass and the reduction of ore splices with overburden rocks. It is proposed to use a charge design of an explosive with inert gaps or a charge section of a cumulative action in the explosive destruction of rocks with contact zones. The influence of parameters of explosive destruction of mining blocks of complex geological structure on the formation of technological complexes of ore beneficiation in quarries is established. The dependence of the factor of stability of slopes of slopes during excavation of rocks, depending on the geological parameters. Scientific novelty. The regularities of changes in the parameters of the ore mass flow (medium piece and oversize) are established depending on the diameter of the drilling-blast wells, which allows you to adjust the particle size distribution. Practical significance. Based on the established patterns and improvement of the design of well charges, their influence on the quality of the blown-up rock mass in the ledges of a complex geological structure has been substantiated, which makes it possible to form the corresponding technological complexes of ore dressing in quarries. The result is a significant increase in the productivity of the technological equipment of the mining enterprise and the profitability of iron ore mining. Key words: quarry, ledge, complex geological structure, downhole charge structures, particle size distribution.
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Lei, Yun. "Reconstruction and Analysis of Tight Sandstone Digital Rock Combined with X-Ray CT Scanning and Multiple-Point Geostatistics Algorithm." Mathematical Problems in Engineering 2020 (June 23, 2020): 1–10. http://dx.doi.org/10.1155/2020/9476060.
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Unconventional rocks such as tight sandstone and shale usually develop multiscale complex pore structures, with dimensions ranging from nanometers to millimeters, and the full range can be difficult to characterize for natural samples. In this paper, we developed a new hybrid digital rock construction approach to mimic the pore space of tight sandstone by combining X-ray CT scanning and multiple-point geostatistics algorithm (MPGA). First, a three-dimensional macropore digital rock describing the macroscopic pore structure of tight sandstone was constructed by micro-CT scanning. Then, high-resolution scanning electron microscopy (SEM) was performed on the tight sandstone sample, and the three-dimensional micropore digital rock was reconstructed by MPGA. Finally, the macropore digital rock and the micropore digital rock were superimposed into the full-pore digital rock. In addition, the nuclear magnetic resonance (NMR) response of digital rocks is simulated using a random walk method, and seepage simulation was performed by the lattice Boltzmann method (LBM). The results show that the full-pore digital rock has the same anisotropy and good connectivity as the actual rock. The porosity, NMR response, and permeability are in good agreement with the experimental values.
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Chékaraou, Mahamane M. S., and Moussa Konaté. "Permian Ages of “Younger Granites” from Mounio Province (Gouré area, Southeastern Niger)." European Journal of Environment and Earth Sciences 2, no. 6 (2021): 27–35. http://dx.doi.org/10.24018/ejgeo.2021.2.6.220.
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African formations intruded by the “Younger Granites” ring complex. In the study area, the “Younger Granites” are represented by volcanic to acid plutonic rocks with hyperalkaline trends (pyroclastic rocks, rhyolites, microgranites, granites, syenites), forming in the North, a circular structure called Gouré ring complex. Preliminary geochronological datings of the Mounio granites have yielded Carboniferous ages. However, recent investigations carried out in this province have identified structures similar to Pan-African deformation structures, such as folds and several generations of schistosity/foliation. Analysis of the relationship between deformation and magmatism has removed any ambiguity regarding the relative age of the deformation. This study focuses on the radiometric dating of the “Younger Granites” of Gouré area, in order to update the geochronological data. Thus, three samples (pyroclastitic rock, rhyolite, microgranite) were dated by the K-Ar method on total rock using a mass spectrometertype MI 1201 IG. Radiometric dating results assign a Lower Permian age (293-287 Ma) to the “Younger Granites” Ring Complex of the Mounio Province in Niger, classically considered to be Carboniferous in age.
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Golik, Vladimir, Galina Stas, Vladimir Morkun, Natalia Morkun, and Irina Gaponenko. "Study of rock structure properties during combined stopping and development headings." E3S Web of Conferences 166 (2020): 03006. http://dx.doi.org/10.1051/e3sconf/202016603006.
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The purpose of this study is to establish the mechanism of interaction between stresses and strains and their quantitative values at the intersection of stopping and development headings to optimize methods for controlling the behaviour of the rock massif. The research complex includes priority methods with experimental confirmation of the calculated parameters by geophysical studies, including stress calculation by a sensor system and surveying levelling to measure deformations using support frames. The properties of the massif and the role of faults and macro-cracks in the development of a field of a complex structure are systematized. A method for studying the stresses and deformations of rocks at the intersection of stopping and development headings is given. The patterns of the rock massif behaviour at the point of intersection are established. The article provides quantitative values of changes in the physical and mechanical properties and stability of rocks at the point of intersection. Massif was differentiated according to the magnitude of the effective stresses in different phases of the intersection. Stresses for specific conditions were calculated with the determination of the reliability of the mining site. The patterns of change in stresses and strains in time are noted.
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Saveliev, Dmitry Evgenievich, Rim Khakimovich Masagutov, and Sergey Nikolaevich Sirota. "MINERALOGICAL FEATURES AND SUBSOLIDUS STRUCTURES OF IZRANDITES FROM ALEXANDROVSK COMPLEX." Geologicheskii vestnik, no. 2 (July 14, 2022): 30–47. http://dx.doi.org/10.31084/2619-0087/2022-2-3.
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This article presents the results of studying the compositions of rock-forming and accessory ultramafic minerals of izrandite samples from Alexandrovsk metamorphic complex. It was found that petrographical, mineralogical and compositional features indicate igneous cumulative origin of studied rocks but amazing freshness of izrandite contradict with their “oldest age”. Together with igneous, numerous occurrences of subsolidus structures were found in studied rocks. These are following: reaction rims on the olivine-plagioclase boundaries, orthopyroxene-pargasite symplectite intergrowths on the olivine-augite and olivine-plagioclase boundaries, ilmenite and Ti-magnetite lamellae in clinopyroxene and amphibole grains, Ti-magnetite solid-solution breakdown structures. It is shown that spinel group mineral grains have complex structure including different blocks: Ti-magnetite with ilmenite exsolution lamellae, homogenous ilmenite and high-Al spinel, and these were probably formed by subsolidus processes. We have considered critically some scenarios of izrandite origin. We infer that izrandites are similar to cumulative rocks from some cratonic layered intrusions, but it is necessary to note that there is no hard evidence of that izrandite is relict of the oldest protolith of metamorphic rocks.
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Liu, Yuan Liang, and Xiao Feng Xie. "Research on Technology of Abandoned Quarry Complex Rock Slope Stability Calculation." Applied Mechanics and Materials 638-640 (September 2014): 542–48. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.542.
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For the abandoned quarry complex rock slope project, the slope stability calculation is always the key technical problem, but due to the complex geological conditions and other factors, it makes the calculation of 3D modeling and the stability of the slope geological body and structure of the division, rock unit has always been the difficult problems in the field. This paper proposes a new method based on the rock mass structure combined with the degree of rock mass element, and then FLAC 3D, Midas GTS three-dimensional numerical calculation software are used, structure and surface topography in the slope, the slope surface fault, soft interlayer, complex geological 3D modeling, overcomes the problem of modeling of complex geological body, and the factors of rainfall, earthquake effect of the slope are consider for stability calculation, the calculation result is consistent with the reality, it has certain directive significance to the abandoned quarry re-greening slope stability analysis.
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Lapatsin, S. N., M. A. Zhuravkov, and P. S. Piaredryi. "Complex estimation of the underground excavations stability in various mining and geological conditions." Proceedings of the National Academy of Sciences of Belarus. Physical-technical series 69, no. 4 (2025): 340–52. https://doi.org/10.29235/1561-8358-2024-69-4-340-352.
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The paper demonstrates a methodology of a complex stability estimation for underground mining excavations located in salt rock masses. Various geological structures of the rock mass, as well as the most popular safety measures for underground excavations support such as ankers, expansion gaps and reinforced concrete are considered. The proposed methodology is based on a hybrid numerical-analytical method for the determination of the stress-strain state of geotechnical systems as well as on an original complex limit state criterion for rock masses. As the result of the study the main factors influencing the stability of excavations where highlighted and generalized. These factors are: mining depth, mechanical properties of rock mass, its geological structure and safety measures. The degree of the importance of each mentioned factor is established. A number of model problems are solved to prove the efficiency of the proposed method for complete and reliable estimation of rock mass state in the vicinity of underground excavations, as well as predicting the stability of geotechnical structures under various conditions.
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Mousavi, Maryam, Maša Prodanovic, and David Jacobi. "New Classification of Carbonate Rocks for Process-Based Pore-Scale Modeling." SPE Journal 18, no. 02 (2012): 243–63. http://dx.doi.org/10.2118/163073-pa.
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Summary Carbonate rocks are complex in structure and pore geometry and display heterogeneity on all length scales. In this paper, carbonate rocks are described on the basis of their contents and pore geometry for use in pore-scale modeling. Definitions of grains and porosities are based on other carbonate-rock classifications; we did not invent new concepts. On the basis of carbonate content (grain, mud, and cement), carbonate rocks were divided into three types: muddy, grainy, and mixed. Each type was divided into subtypes on the basis of pore geometries defined by other researchers. Pore-size distribution of Lønøy (2006) was used for each subtype. We review existing carbonate-rock models and suggest approaches, and show preliminary flow-simulation results, for pore-scale modeling of different grains, cement, and pore geometry in these complex rocks.
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White, Gemma E., and Culum Brown. "Microhabitat Use Affects Brain Size and Structure in Intertidal Gobies." Brain, Behavior and Evolution 85, no. 2 (2015): 107–16. http://dx.doi.org/10.1159/000380875.
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The ecological cognition hypothesis poses that the brains and behaviours of individuals are largely shaped by the environments in which they live and the associated challenges they must overcome during their lives. Here we examine the effect of environmental complexity on relative brain size in 4 species of intertidal gobies from differing habitats. Two species were rock pool specialists that lived on spatially complex rocky shores, while the remainder lived on dynamic, but structurally simple, sandy shores. We found that rock pool-dwelling species had relatively larger brains and telencephalons in particular, while sand-dwelling species had a larger optic tectum and hypothalamus. In general, it appears that various fish species trade off neural investment in specific brain lobes depending on the environment in which they live. Our previous research suggests that rock pool species have greater spatial learning abilities, enabling them to navigate their spatially complex environment, which may account for their enlarged telencephalon, while sand-dwelling species likely have a reduced need for spatial learning, due to their spatially simple habitat, and a greater need for visual acuity. The dorsal medulla and cerebellum size was unaffected by the habitat in which the fish lived, but there were differences between species indicative of species-specific trade-offs in neural investment.
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Pollok, Lukas, and Mareike Henneberg. "Sub-areas in steep rock salt formations – what do we know about the geological composition of North German salt structures?" Safety of Nuclear Waste Disposal 1 (November 10, 2021): 73–74. http://dx.doi.org/10.5194/sand-1-73-2021.
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Abstract. Suitable host rocks for a repository for high-level radioactive waste (HLW) in Germany include not only clay and crystalline rocks but also rock salt formations in so-called flat and steep bedding (StandAG, 2017). Favourable repository relevant properties of rock salt are, e.g. the high heat conductivity, low porosity and permeability, and its viscoplastic deformation behaviour. Thicker salt deposits can be attributed to the formation of approx. 700 salt structures that have formed under various geological conditions in the North German Basin (NGB) over the last 250 million years. According to their shape and genesis, salt structures are classified as salt pillows (considered as flat bedding) or salt diapirs (steep bedding). Out of a total of 74 sub-areas in rock salt, 60 sub-areas in salt diapirs consisting of Permian evaporates were identified within the first phase of the German site selection procedure (BGE, 2020). At the current stage of the site selection process, a conservative approach has been adopted and the internal structure of the salt structures have not yet been taken into account for further classification of the identified sub-areas. However, the interior of the salt structures not only consists of rock salt but also of varying proportions of clay, carbonate and anhydrite rocks, as well as potassium salts formed by progressive evaporation of marine brines. Multi-phase salt tectonics has led to the folding of these differently composed layers and to complex internal structures. Therefore, detailed knowledge of the salt structure compositions is necessary to identify suitable rock salt areas for the designation of the containment providing rock zone. As a result of decades of research through extensive salt and potash mining, cavern storage and exploration for final waste disposal, Permian salt rocks represent a well-studied host rock in Germany. The use of different exploration methods and multidisciplinary data evaluation have led to a comprehensive understanding of the internal composition of some well-studied salt structures. Systematic studies have shown that several factors have influenced the formation of salt structures as well as their external shapes, sizes, and spatial distribution (e.g., Pollok et al., 2020). Furthermore, the amount and distribution of suitable host rocks varies greatly in different salt structures and is closely related to their internal structure. Since the interior of salt structures has not been considered in the site selection process so far, a classification of salt structures (or sub-areas) into certain types with varying internal composition and complexity is presented. By examining their lithofacial composition, genesis, and structural geological position within the basin, it is possible to narrow down these types to specific areas in the NGB. Without the acquisition of additional exploration data in this phase of the site selection process, this salt structure classification provides important data for the legally demanded assessment of the overall favourable geological situation.
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Li, Yu Sheng, Guang Peng Cao, and Jie Bao. "Dynamic Numerical Simulation for the Problem of Tunnel Rock Mass Large Deformation of a Hydropower Project in the Upper Reaches of Lancang River." Advanced Materials Research 250-253 (May 2011): 1315–19. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1315.
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It is a very effective technology methods that using dynamic numerical simulation of discrete element method to study the large deformation problems of underground engineering rock mass which in the complex rock mass mechanics environmental conditions.Research achievements show that the development of deformation failure of the tunnel surrounding rock and the final convergence stability are mainly controlled by rock mass structure and its stress environment in the special toppling deformation rock mass. Deformation of the rock mass that in the lateral unloading and relaxation and also has a complex rock mass structure developed sustainably and progressivity over time,will eventually seriously damaged in roof fall. The surrounding rock deformation of the tunnel ,which have a good rock mass integrity and do not have the obvious unloading and relaxation stress environment, gradually tended to be stable after the initial deceleration-type development.
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Zhang, Biao, Huaqiang Zhou, Qingliang Chang, Xu Zhao, and Yuantian Sun. "The Stability Analysis of Roadway near Faults under Complex High Stress." Advances in Civil Engineering 2020 (December 2, 2020): 1–10. http://dx.doi.org/10.1155/2020/8893842.
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Based on geological conditions of 3318 working face haulage roadway in Xuchang Coal Mine, as well as the space-time relationship with surrounding gob, theoretical analysis and numerical simulation were used to study the influence of fault structure on the original rock stress of 3318 working face transport roadway. Considering the composite action of the leading supporting pressure of 3318 working face and the structure and the lateral supporting pressure of gob, the stress distribution and deformation law of roadway under the complex and high-stress condition are studied. The results show that, under the superposition of lateral abutment pressure of goaf and abutment pressure of adjacent working face and fault structure, the peak stress of roadway roof and floor moves to the surface of roadway surrounding rock, and its distribution law changes from obvious symmetry to asymmetry; surrounding rock on both sides of roadway forms asymmetric circular concentrated stress area; roof and floor and two sides of roadway show asymmetric characteristics. This reveals the stability characteristics of roadway surrounding rock under the action of multiple perturbation stresses.
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Ye, Dayu, Guannan Liu, Feng Gao, Xinmin Zhu, and Yuhao Hu. "A Study on the Structure of Rock Engineering Coatings Based on Complex Network Theory." Coatings 10, no. 12 (2020): 1152. http://dx.doi.org/10.3390/coatings10121152.
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As one of the most basic materials of engineering coatings, rock has complex structural characteristics in its medium space. However, it is still difficult to quantitatively characterize the microstructure of rock coatings, such as connectivity and aggregation degree. For this paper, based on a CT-scan model of rock coating, we extracted the network topology of a rock coating sample and verified that its microstructure parameter distribution accords with Barabasi and Albert (BA) scale-free theory. Based on this result, relying on the BA scale-free theory, a dual-porosity network model of rock coating was constructed. We extracted the network structure of the model to verify it, and analyzed the distribution of the microstructure parameters of the model, such as degree distribution, average path length and throat length distribution. At the same time, we analyzed the evolution trend of the permeability of the coating model with the microscopic parameters. Then we discuss the influence of the change of structural parameters on the microstructure of the coating model, and compared with the mainstream rock models at the present stage, the rationality and accuracy of the models are analyzed. This provides a new method for studying the mechanical and permeability properties of engineering coating materials.
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Kassymkanova, K. K., K. B. Rysbekov, M. B. Nurpeissova, et al. "GEOPHYSICAL STUDIES OF ROCK DISTORTION IN MINING OPERATIONS IN COMPLEX GEOLOGICAL CONDITIONS." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVIII-5/W2-2023 (June 13, 2023): 57–62. http://dx.doi.org/10.5194/isprs-archives-xlviii-5-w2-2023-57-2023.
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Abstract. Geophysical methods of rock mass survey are one of the most effective ways of solving various problems in mining and are widely used in mining, gas and oil industries, as well as in science. They allow carrying out prospecting and evaluation works remotely, to reveal structural heterogeneities, cavities, contact zones of different media in rock mass with rather high accuracy. At the stage of designing a mining enterprise and making major decisions, it is necessary to have reliable information about the tectonic structure of the undermined and adjacent massif and parameters of its geodynamic activity. For this purpose, special studies of the tectonic structure of the rock massif must be carried out and the parameters of modern geodynamic movements must be determined. The most complete information about tectonic disturbances, identification of gliding surfaces, zones of macrofracturing are provided by geophysical methods of rock mass survey.In the article analysis of study of structural-tectonic structure of ore areas, separation and specification of ore-controlling structures, detection and depth mapping of ore-controlling faults, volume mapping of intrusive massifs based on previously conducted geophysical research in Zhezkazgan syncline area carried out. Geological and geophysical conditions of the central ore field (presence of rich bodies with high electric conductivity, considerable thicknesses of ore bodies, etc.) were favorable for application of various geophysical methods to search and trace rich ore bodies occurring at low depths.Moreover, possibilities of application of seismic works are considered at the solution of problems of ore geology in difficult mining-geological conditions of Kazakhstan.
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Wan, Li-rong, Zhe Li, Yang Yang, and Ran Li. "Analysis on the Difference of Impact Response between Single Coal-Rock Particle and the Box Structure-Based Tail Beam." Shock and Vibration 2021 (February 4, 2021): 1–15. http://dx.doi.org/10.1155/2021/6688964.
Full textAbstract:
In the process of coal caving, the basis of identifying coal and rock by the vibration signal is the difference of the tail beam response when coal-rock impacts the tail beam, and the tail beam in the hydraulic support is a complex box structure with multiplate transverse and longitudinal welding, and the response difference of the box structure-based tail beam under the impact of coal-rock is not clear. Therefore, this paper studies the response difference of box structure-based tail beam when coal-rock particle impacts on the box structure-based tail beam. Firstly, through the construction and analysis of the impact theoretical model of the coal-rock particle and metal plate, it is found that the complex box structure of the tail beam makes it extremely difficult to establish the impact theoretical model of the coal-rock and box structure-based tail beam, so it is impossible to directly study the response of the box structure-based tail beam when the coal-rock impacts on the box structure-based tail beam by the theoretical method. Therefore, the impact simulation model of coal-rock particle and box structure-based tail beam is further established. Through the changes of kinetic energy and internal energy of the box structure-based tail beam system, the contact response of collision contact zone, and noncollision contact zone of the box structure-based tail beam, the response difference of box structure-based tail beam when coal-rock particle impacts on the box structure-based tail beam is analyzed. Then, by changing the impact speed and contact mode of the coal-rock particle, the effects of impact speed and the contact mode on the response difference of the box structure-based tail beam are studied separately. The conclusion shows that the response difference of the box structure-based tail beam under the impact of the coal particle and rock particle is obvious, and the difference increases as the impact speed increases, and the difference increases as the contact range increases.
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Dong, Jun, Qingqing Chen, Guangxiang Yuan, and Kaiyan Xie. "Rock Mass Structure Classification of Caves Based on the 3D Rock Block Index." Applied Sciences 14, no. 3 (2024): 1230. http://dx.doi.org/10.3390/app14031230.
Full textAbstract:
In large-scale water conservancy and hydropower projects, complex rock structures are considered to be the main factor controlling the stability of hydraulic structures. The classification of rock mass structure plays an important role in the safety of all kinds of large buildings, especially underground engineering buildings. As a quantitative classification index of rock mass, the rock block index is very common in the classification of borehole and dam foundation rock mass structures. However, there are few studies on the classification of underground engineering rock masses. Moreover, their classification criteria have disadvantages in spatial dimension. Therefore, this paper takes the long exploratory cave CPD1 in the water transmission and power generation system of the Qingtian pumped storage power station in Zhejiang Province as the research object and launches a study on the structural classification of the rock mass of a flat cave based on the 3D rock block index. According to the group distribution of joints, the sections are statistically homogeneous. Additionally, the Monte Carlo method is used to carry out random simulations to generate a three-dimensional joint network model. The virtual survey lines are arranged along the center of the shape of the three different orthogonal planes of the 3D joint network model to represent the boreholes, and the RBI values of the virtual survey lines on each orthogonal plane are counted to classify the rock mass structure of the flat cave in a refined manner using the rock block index of the rock mass in 3D. The above method realizes the application of the 3D rock block index in underground engineering and overcomes the limitations of traditional rock mass classification methods in terms of classification index and dimension. The results show that: (1) Three-dimensional joint network simulations built on statistical and probabilistic foundations can visualize the structure of the rock mass and more accurately reflect the structural characteristics of the actual rock mass. (2) Based on the 3D rock block index, the rock mass structure of the long-tunnel CPD1 is classified, from that of a continuous structure to a blocky structure, corresponding to the integrity of the rock mass from complete to relatively complete. The classification results are consistent with the evaluation results of horizontal tunnel seismic wave geophysical exploration. (3) Based on the 3D joint network model, it is reasonable and feasible to use the 3D rock block index as a quantitative evaluation index to determine the structure type of flat cave rock masses. The above method is helpful and significant in the classification of underground engineering rock mass structures.
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Soltan, Basim H. "Petrology and stratigraphy of pre-Cambrian Hormuz Series outcrops in Jabal Sanam structure - the oldest surface rocks in Iraq." BASRA JOURNAL OF SCIENCE 38, no. 3 (2020): 497–520. http://dx.doi.org/10.29072/basjs.202039.
Full textAbstract:
Detailed geological field investigations have been done at Jabal Sanam structure Southern Iraq. More than 150 rock and mineral represented samples were collected, and 130 thin sections of these samples were prepared and examined microscopically. An accurate mineralogical study of these rocks by analysis of 15 samples with the X-ray diffraction technique was achieved. A large number of sedimentary rocks were distinguished through field observations and petrographic studies, such as gypsum, limestone, dolomite, red and green marl, sedimentary ironstones, chert, and salts. Various types of igneous and metamorphic rocks such as dolerite, schist, slate, and metamorphic sediments were found as beds or fragments intruded with the evaporite rocks of Jabal Sanam. Distinct mineralizations of hematite, pyrite, and dolomite minerals were observed in these successions. It was noted also, that these rocks were subjected to varied geological processes of different degrees that affected their original rock characteristics such as diagenesis, metamorphism, deformation, and dissolution processes. A petrological, stratigraphic, and tectonic correlation has been made with similar structures spread through the region (Iran and Arabian Peninsula) in the light of their composition which, in general; consists of infra-Cambrian evaporates of Hormuz Series. This study supports the previous geological studies on this salt structure, shows a great similarity between the rocks of Hormuz Series Complex and those of Jabal Sanam, which may be considered in terms of stratigraphy and petrology as equivalent rock units. Thus, these rocks may be suggested as the oldest rocks exposed above the earth’s surface in Iraq
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Kozhoukharov, Dimitar, Emil Vasilev, and Evgenia Kozhoukharova. "Lithostratigraphy of the Ordovician System in the Lozen Mountain." Geologica Balcanica 33, no. 3-4 (2003): 3–14. http://dx.doi.org/10.52321/geolbalc.33.3-4.3.
Full textAbstract:
In the Lozen Mountain the rocks of the Ordovician System differ from the Ordovician rocks in the western Balkan Mts. in their composition, structure and relationship to the underlying diabase-phyllitoid complex. In the present paper they are described as a formal lithostratigraphic unit named Kroushovitsa Formation, which comprises four members. In ascending order these members are: Souha Gabra Member comprising metaconglomerates, meta-psammites with fragments of green schists, meta-tuffs and quartzites of the diabasephyllitoid complex; Choukite Member built of graygreenish phyllitized siltstones; Chouchouralchal Member comprising red phyllitized siltstones intercalated with yellow to light red meta-psammites, and Kitka Member represented by gray-greenish phyllitized siltstones intercalated with lamina of dark-gray to black argillites and siltstones. All rock varieties in the Kroushovitsa Formation have been subjected to week metamorphic alteration in greenschist facies that progressively attenuates from the lower to the upper levels of the section. The rock composition, structure and texture of the sequence in the Kroushovitsa Formation indicate for predominantly deep-sea sedimentation. In the lower part of the formation coarse clastic rocks indicate a shallowwater shelf environment.
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Isyqi, Nugroho Imam Setiawan, and Ferian Anggara. "Preliminary Study of the Graphite Phyllite Rock from the Luk Ulo Melange Complex, Central Java, Indonesia." IOP Conference Series: Earth and Environmental Science 1378, no. 1 (2024): 012029. http://dx.doi.org/10.1088/1755-1315/1378/1/012029.
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Abstract Phyllite rocks containing graphite minerals are exposed at the Luk Ulo Melange Complex (LUMC), Central Java, Indonesia. This study aims to determine the occurrence, petrographic, and geochemical characteristics of the LUMC phyllite rocks. The method used in this research consists of field observation and laboratory analysis, including petrographic and geochemical analysis using ICP AES/MS. Field observations were carried out in six locations, namely in the Karangsambung, Totogan, Duren, Kebondalem, Kebutuhjurang, and Pesangkalan villages. The phyllites are present as blocks in LUMC with 2 to >10 m in dimension and are associated with other metamorphic rocks such as greenschist, quartzite, and marble. LUMC phyllite rock has a fresh grey-black color, phyllitic foliated structure, and lepidoblastic texture. The main minerals are graphite, muscovite, quartz, and chlorite. Whole rock geochemical analysis was carried out on a phyllite sample from the Karangsambung area and showed that the major elements that dominated were SiO2 (69 wt%), Al2O3 (13 wt%), and Fe2O3 (5.78 wt%) that typical of metapelite rocks.
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RYLNIKOVA, M. V., E. M. SAKHAROV, and E. N. ESINA. "PERSPECTIVE FOR IMPROVING THE METHODS OF FIXING MINE WORKINGS IN SALT ROCKS OF DIFFERENT STRENGTH." News of the Tula state university. Sciences of Earth 3, no. 1 (2023): 268–79. http://dx.doi.org/10.46689/2218-5194-2023-3-1-268-279.
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Ensuring the operability of the support of mine workings supported in various conditions of subsurface development is one of the most important and difficult to solve problems in the mining industry. The reason for the low stability of underground workings is the insufficient bearing capacity of anchors, especially with a long service life. A decrease in the bearing capacity of the anchor support over time occurs as a result of natural processes of deformation of rocks, a decrease in strength and corrosion of the support elements in aggressive environments. With the weakening of the bearing capacity of the anchors, the displacements of the rock contour of the workings increase, the number and width of cracks in the roof rocks increases, local rock falls and local blockages of mine workings appear. It is shown that the choice of the type, structure and parameters of the anchor support that ensures the stability of deep-lying underground mine workings in a complex-structured, multi-strength, multi-modular array of layered enclosing rocks with complex morphology and the presence of flexural disturbances of the silvinite formation of a potash deposit should be made differentially taking into account the geological structure of the array behind the contour of the workings, which determines the specifics of loading components along the length of the anchor.
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Lamzamuan, G., Sorokhaibam Kavita Devi, and Liza Gogoi. "Unraveling the Protolith Origin of Serpentinite Rocks from the Tengnoupal Area, Manipur Ophiolite Complex, Indo-Myanmar Range." Indian Journal Of Science And Technology 17, no. 36 (2024): 3719–32. http://dx.doi.org/10.17485/ijst/v17i36.2279.
Full textAbstract:
Objective: This article mainly focuses on investigating the protolith origin of serpentinite rocks in and around Tengnoupal, within the Manipur Ophiolite Complex (MOC), using a combined petrographic and geochemical approach. Methods: During fieldwork, samples were collected and cut into thin sections to reveal their mineralogical and textural relationships. Major oxides and trace elements were determined by XRF, and rare earth elements analysis was carried out by ICP-MS to determine the nature and origin of the rocks. Findings: The studied rock samples exhibit varying degrees of serpentinization, ranging from partial to complete, and exhibit a pseudomorphic texture including mesh and hour structures replacing the original olivine and bastite texture replacing pyroxene. Geochemically, the analyzed rock types exhibit komatiitic affinity and are characterized by high magnesium numbers (Mg# average 84.4). The studied serpentinite rocks have lower Al/Si ratios (Average=0.05) and higher Mg/Si ratios (average= 0.95) in bulk rock compositions indicating a refractory abyssal mantle peridotite protolith when compared to the primitive mantle. The high Ti (range 300-480 ppm) and Cr (628-3186 ppm) contents indicate a subduction environment. In addition, the rock samples exhibit slight depletion chondrite-normalized Rare Earth Elements (REE) patterns ((La/Yb) N = average 0.87). The rocks exhibit spoon-shaped normalized Rare Earth Element patterns and primitive mantle are similar to mid-oceanic ridge abyssal mantle rocks. Novelty: The origins of the rocks studied suggest a transitional phase between abyssal and subduction zone-related serpentinites, forming after harzburgite-peridotite. As subduction began, dehydrated orogenic peridotite from the abyssal serpentinites was thrust or obducted, forming the MOC serpentinites. This indicates that the serpentinite rocks in MOC share similarities with those found in mid-oceanic ridge environments, which is characteristic of a supra-subduction zone setting. Keywords: Ultramafic rocks, Serpentinization, Suprasubduction zone, Abyssal, REE
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Zhang, Yiqiang, Siarhei Lapatsin, Michael Zhuravkov, Guangbin Yu, and Ivan Karpovich. "The Stability and Failure of Deep Underground Structures at Potash Mining Deposits." Applied Sciences 14, no. 20 (2024): 9434. http://dx.doi.org/10.3390/app14209434.
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The article describes the peculiarities of strength and stability evaluation for deep geotechnical structures located in salt rock masses at great depths. A number of numerical studies are presented for the deep mining excavations of various cross-sections. The numerical simulations are conducted using a specific coupled algorithm of the finite element method (FEM) and distinct element method (DEM), which allows not only the prediction of dangerous zones in the undermined rock mass but also to simulation of the block fracture of the rock mass directly. Potential critical zones in the rock mass are established using an original complex limit state criterion for rock masses and FEM simulation results. Mentioned original criterion is a specific multicriterial method, which considers potential tensile, compressive and shear failure as well as crack propagation. To define the block-structure formulation in the rock mass it is proposed to use the Lade criterion in the complex limit state zones. Furthermore, block-structured rock mass behavior is simulated using DEM to predict its block-like fracture. The results of numerical studies clearly show that the mechanical behavior of potash salt rock masses significantly differ at moderate and great mining depths. Namely, the volume of the limit state zones nonlinearly increases with the increase in the mining depths up to double the size of the excavation cross-section. However, the exact amount of potentially failed rock mass has to be established using the direct DEM simulation in the limit state zones.
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Stephens, Richard B., and Ping Sheng. "Acoustic reflections from complex strata." GEOPHYSICS 50, no. 7 (1985): 1100–1107. http://dx.doi.org/10.1190/1.1441982.
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Rock strata may contain fine‐scale structures which are too small to be identified directly, but which can give rise to anomalous seismic reflection amplitudes. The variance caused by such anomalies severely hampers the use of reflection amplitudes for layer identification, and techniques are required which can identify or correct for the effects of such fine structure. We have done calculations which explore the consequences of two general structure types: wavy interfaces and very thin layers. In each case, a formalism is set up which enables us to identify systematically all of their effects. Computer modeling of realistic formations verified our calculations. We suggest that the strongly wavelength‐dependent response of such layers and their characteristic response waveforms may provide convenient tools for identifying fine‐scale features in strata.
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Ishchenko, O. K., and O. P. Strilets. "Efficiency and seismic safety of constructing underground structures in complex rock masses." Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, no. 6 (December 23, 2023): 67–72. http://dx.doi.org/10.33271/nvngu/2023-6/067.
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Purpose. To develop new resource-saving method of underground construction and evaluate how effective it is, to set thresholds for safe seismic ground vibrations which accompany explosions during breaking in mine workings. Methodology. The work used method of analysing mining and geological conditions of workings, field surveys of rock conditions in face, experiments are conducted on rock samples taken from blasting sites, more detailed data are obtained on rock properties, type and direction of development of crack systems along the workings cross-section by funneling method and approved research methods in accordance with current State Standards. Findings. Research has been carried out to determine main features of physical and mechanical properties of rocks, fracture and tectonic structure of rock mass and development of fracture systems. According to the results of ejection funnel parameters, the anisotropy coefficient was calculated, and according to data on identification of crack systems and their density, fracture coefficient was calculated. The experimental data obtained were used to adjust rational distances between contour boreholes and along the entire cross-section of working face. Based on corrected drilling and blasting operations (DBO), experimental explosions were carried out in workings. It was established that the borehole utilisation rate (BUR) was 0.95–0.97, uniformity of rock mass crushing was achieved, and explosive material consumption was reduced by 10–15 %. Instrumental measurements of explosion impact in workings proved seismic ground vibrations at protected facilities amounted to 0.4 cm/s with a duration of 0.05 s, which did not exceed the State Standard. Originality. Optimal DBO parameters are substantiated based on changes in numerical parameters of anisotropy and fracture coefficient, as well as radius of fracture zone along the cross-section of working face. The idea of forming a shielding zone along the contour of workings with explosive charges having an elongated symmetrical cut was confirmed and technically implemented. Practical value. Laboratory and field research results are fundamental for designing borehole layouts along workings and refer to major initial data used to justify design parameters of blasting chart.
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Fedoriv, V. V. "The use of gamma-spectrometry and gamma-gamma-density logging for the study of reservoir rocks of complex structures." Prospecting and Development of Oil and Gas Fields, no. 2(67) (March 28, 2018): 41–46. http://dx.doi.org/10.31471/1993-9973-2018-2(67)-41-46.
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The results of the study of the poroperm properties of the complex structure reservoir rocks of the neogene deposits at the Letnianskyi gas condensate field are considered. The petrophysical model for determining the bulk content of the main components of oil and gas reservoirs is given by data of gamma-gamma-density logging and spectrometric gamma-logging. The petrophysical model of the joint use of the results of gamma-spectrometry and gamma-gamma-density logging is shown.
 As a result of data analysis, it has been established that there is a close relationship between uranium content and bulk density. It should also be noted that there is a close relationship between the solid organic matter and the thorium content.
 It has been shown that under the conditions of complex structure reservoirs, the complex processing of data of gamma spectrometry and gamma-gamma-density logging allows quantitatively to determine the following parameters in complex structures: clayness, porosity, content of solid organic matter and rock density.
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Nelson, S. O., D. P. Lindroth, and R. L. Blake. "Dielectric properties of selected minerals at 1 to 22 GHz." GEOPHYSICS 54, no. 10 (1989): 1344–49. http://dx.doi.org/10.1190/1.1442596.
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Metallurgical mineral separation makes use of the large differences in dielectric properties of individual minerals (Thirumalai, 1970; Jordan et. al, 1980). Microwave heating for thermal rock fragmentation uses differences in the complex electrical properties of rock due to inhomogeneities in composition, structure, and texture. Knowledge of the relative complex permittivity is required to determine the differential absorption of microwave energy in an aggregate of minerals (rock).
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Shkolnik, S. I., V. A. Belyaev, E. F. Letnikova, et al. "BUTUGOL METAMORPHIC COMPLEX – EXOTIC PRECAMBRIAN BLOCK IN THE STRUCTURE OF THE BASEMENT OF THE TUVA-MONGOLIAN MICROCONTINENT (EASTERN SAYAN)." Доклады Российской академии наук. Науки о Земле 510, no. 2 (2023): 127–33. http://dx.doi.org/10.31857/s2686739723600261.
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Isotope-geochronological and geochemical data and age of the metamorphic rock of the Butugol metamorphic Complex, located in the eastern part of the Tuva-Mongolian microcontinent of the CAOB, have been obtained. It has been established that the gneisses protolith is, in one case, volcanic rocks with an age of 1009 ± 8 Ma, in the other case, potassium meta-sedimentary rocks accumulating in continental marginal basins. The formation of the protolith of the metavolcanogenic rocks of this complex took place at the turn of the Meso- and Neoproterozoic on the formed crust, while the metasedimentary rocks formed due to the Mesoproterozoic, more rarely Paleoproterozoic and Archean continental provenances. It has been established that the rocks of the Butugol metamorphic Complex have a different history of development from other blocks of the earth’s crust as part of the composite Tuva-Mongolian microcontinent.
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Musnajam, M., Ahmad Tarmidzi Abd Karim, N. Nurfadillah, Fahrudi Ahwan Ikhsan, and Andri Estining Sejati. "The Facies and Metamorphism Types Determination of Metamorphic Rock in The Part of Mekongga Complex." Geosfera Indonesia 5, no. 2 (2020): 250. http://dx.doi.org/10.19184/geosi.v5i2.17340.
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Lambolemo Village is geomorphologically dominated by hilly slopes morphology. Lithology in the form of metamorphic rocks are mica schists and chlorite schists. The present research aimed to determine the facies and metamorphism types of metamorphic rocks in Lambolemo Village. The research methods engaged were field observation and laboratory observation utilizing petrographic analysis. Observations stage generated texture data and set of mineral both macroscopically and microscopically. The minerals were discovered within metamorphic rock of the research area, namely: muscovite, quartz, biotite, and chlorite. These findings then classified into two zones, there were chlorite zone and biotite zone. These zones were embodied into greenschist facies with chlorite mineral index. The greenschist facies was characterized with chlorite, albit, epidote, and actinolite minerals appearance. The metamorphic rock had a foliation structure. The structure was commonly generated by a regional metamorphic process, which was particularly a feature of the clear alignment, translucent minerals from flat minerals, such as : mica, chlorite and minerals that obtained fibers or scents.
 Keywords: Determination; Facies; Metamorfism Type
 
 Copyright (c) 2020 Geosfera Indonesia Journal and Department of Geography Education, University of Jember
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Si, Xuefeng, Song Luo, and Yong Luo. "A Review of Mechanical Properties and Rockburst Investigation of Transversely Isotropic Rocks by Experimental Technique." Materials 16, no. 8 (2023): 3183. http://dx.doi.org/10.3390/ma16083183.
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Under complex geostress caused by long-term geological evolution, approximately parallel bedding structures are normally created in rocks due to sedimentation or metamorphism. This type of rock is known as transversely isotropic rock (TIR). Due to the existence of bedding planes, the mechanical properties of TIR are quite different from those of relatively homogeneous rocks. The purpose of this review is to discuss the research progress into the mechanical properties and failure characteristics of TIR and to explore the influence of the bedding structure on the rockburst characteristics of the surrounding rocks. First, the P-wave velocity characteristics of the TIR is summarized, followed by the mechanical properties (e.g., the uniaxial compressive strength, the triaxial compressive strength, and tensile strength) and the related failure characteristics of the TIR. The strength criteria of the TIR under triaxial compression are also summarized in this section. Second, the research progress of the rockburst tests on the TIR is reviewed. Finally, six prospects for the study of the transversely isotropic rock are presented: (1) measuring the Brazilian tensile strength of the TIR; (2) establishing the strength criteria for the TIR; (3) revealing the influence mechanism of the mineral particles between the bedding planes on rock failure from the microscopic point of view; (4) investigating the mechanical properties of the TIR in complex environments; (5) experimentally investigating the rockburst of the TIR under the stress path of “the three-dimensional high stress + internal unloading + dynamic disturbance”; and (6) studying the influence of the bedding angle, thickness, and number on the rockburst proneness of the TIR. Finally, some conclusions are summarized.
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Gintov, O. B., and O. V. Usenko. "Peculiarities of the present structure of the Bug granulite complex developed within the Middle Bug area and its partitioning into series and suits." Geofizicheskiy Zhurnal 44, no. 4 (2022): 3–37. http://dx.doi.org/10.24028/gj.v44i4.264839.
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The Gaivoron-Zavalie site and the Golovanevsk suture zone (GSZ) of the Bug mining region (BMR) in the Middle Bug region have been a «testing ground» for studying the structure and stratigraphy of the Early Precambrian complexes of the USh for many years. In the article, using their example, the Early Precambrian part of the Correlation Chronostratigraphic Scheme of the USh (CCS USh) and the issues arising around its discussion and the need for changes have been considered here. The main problem is to find out series, formations and rock strata in the CCS of USh, which is quite debatable. It has been shown that some rock strata (leucogranulite formation and Zelenolevadov rock strata, a significant part of the Koshar-Alexandrov suite) refer to the formation-genetic series of quartz-feldspar metasomatites, in particular, to the structural-formation association of metasomatites of zones of regional faults and they are not stratigenic. According to isotope-geochronological data, the bereznin rock strata is not Archean and therefore does not belong to the Dniester-Bug series. The layering, banding and gneissovity of the enderbite-gneiss complex of the Gaivoron-Zavalie section are associated with its intersection of a dense network of fault zones and therefore this area refers to the area of development of highly dispersed metamorphic tectonites, rather than the stratigene rock strata, which some researchers try to call the «Salkovska Formation». The association of the iron-ore strata of the Bug mining region into the Pavlov rock strata of the Archean Dniester-Bug series is not correct, because the present overlapped section of such rock strata has been studied in the Moldovian structure in the GSZ structure, and it refers to the Bug series. However, the genesis of iron-ore rocks is disputable, so the authors consider it undesirable to include them in the CCS of the Ukrainian shield. The genesis of graphitic gneisses and quartzites of the Khaschevato-Zavaliev suite is also disputable, which leads to the conclusion that it should be excluded from the CCS of the Ukrainian shield. With the exclusion of the Zelenolevadov, Bereznin, and Pavlov strata from the Dniester-Bug Series, only the strata of hyperstene and dipyroxene plagiogneisses and crystalline schists, called as Tyvrovka, remains in it. Its stratotype becomes the stratotype of the entire series, so the stratum “Tyvrov rock strata” can also be removed from the series. The authors conclude that the division of the Bug granulite complex into suites and rock strata is impractible. When considering the division of the Bug granulite complex into series, it is shown that the concept “series” as set forth in the Stratigraphic Code of Ukraine, although it does not take into account the features of formation of the Archean series, however does not contradict them. Therefore, separation of the Dniester-Bug and Bug series of different composition and age is quite natural. Contrary to the opinions of some researchers on the continuous process of accumulation of sedimentary-volcanogenic rocks of the Middle Bug area, it is shown that the anomalies in the age distribution of clastogenic zircons from the rocks of the Gaivoron-Zavalie and GSZ correspond to the global one and reflect a worldwide process of crustal formation, in which relatively quiet tectonic regimes alternated with periods of tectonic activation. During such periods, both magmatic and metasomatic processes and sedimentary-volcanogenic processes were activated. Materials of the study of the hafnium isotope composition from the zircons of the Dniester-Bug and Bug series rocks indicate a possible difference in the age of their formation of 600—700 Ma. The questions of the origin and rearrangement of the Bug granulite complex developed in the study area are also considered here.
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Zagranovskaya, D. E., S. I. Isaeva, A. P. Vilesov, et al. "Structure of continues reservoirs in the Domanik formation and petrophysical interpretation methods." Moscow University Bulletin. Series 4. Geology 1, no. 6 (2022): 120–32. http://dx.doi.org/10.33623/0579-9406-2021-6-120-132.
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Properties of unconventional prospective deposits are interconnected by the rocesses of reservoir formation and oil and gas formation. Dispersed dolomite in situ formed during the maturation of TOC from syngenetic magnesium in the rock matrix increases the void space of the rock, thereby forming an unconventional reservoir filled with autochthonous hydrocarbons and oil components. In the process of TOC maturation and hydrocarbon migration, the TOC components are redistributed in the void space, thereby, the released volume of rocks is filled with stationary resinous asphaltene substances, which sharply reduces the reservoir properties of unconventional reservoirs. As a result, the definition of “organic” porosity includes a broader concept than just the porosity of kerogen. This is a more complex physicochemical process of transformation of the organic matter itself and the redistribution of elements within the formation as a result of the maturation of TOC components and hydrocarbon migration. When assessing the oil and gas potential in the section, we distinguish three groups of rocks: unconventional reservoirs with an increased TOC content and the presence of mobile hydrocarbons; bituminous rocks, in which part of the pore volume is filled with resinous-asphaltene substances and host dense carbonate rocks without organic matter. Also, sporadically developed traditional reservoirs are distinguished throughout the section of the Domanik type of rocks.
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Gonçalves, Laercio B., and Fabiana R. Leta. "Macroscopic Rock Texture Image Classification Using a Hierarchical Neuro-Fuzzy Class Method." Mathematical Problems in Engineering 2010 (2010): 1–23. http://dx.doi.org/10.1155/2010/163635.
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We used a Hierarchical Neuro-Fuzzy Class Method based on binary space partitioning (NFHB-Class Method) for macroscopic rock texture classification. The relevance of this study is in helping Geologists in the diagnosis and planning of oil reservoir exploration. The proposed method is capable of generating its own decision structure, with automatic extraction of fuzzy rules. These rules are linguistically interpretable, thus explaining the obtained data structure. The presented image classification for macroscopic rocks is based on texture descriptors, such as spatial variation coefficient, Hurst coefficient, entropy, and cooccurrence matrix. Four rock classes have been evaluated by the NFHB-Class Method: gneiss (two subclasses), basalt (four subclasses), diabase (five subclasses), and rhyolite (five subclasses). These four rock classes are of great interest in the evaluation of oil boreholes, which is considered a complex task by geologists. We present a computer method to solve this problem. In order to evaluate system performance, we used 50 RGB images for each rock classes and subclasses, thus producing a total of 800 images. For all rock classes, the NFHB-Class Method achieved a percentage of correct hits over 73%. The proposed method converged for all tests presented in the case study.
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Hu, Yuhao, Guannan Liu, Feng Gao, Fengtian Yue, and Tao Gao. "A Complex Network Approach for Quantitative Characterization and Robustness Analysis of Sandstone Pore Network Structure." Geofluids 2021 (April 6, 2021): 1–10. http://dx.doi.org/10.1155/2021/6671829.
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The rational characterization and quantitative analysis of the complex internal pore structure of rock is the foundation to solve many underground engineering problems. In this paper, CT imaging technology is used to directly characterize the three-dimensional pore network topology of sandstone with different porosity. Then, in view of the problem, which is difficult to quantify the detailed topological structure of the sandstone pore networks in the previous study, the new complex network theory is used to characterize the pore structure. PageRank algorithm is based on the number of connections between targets as a measure index to rank the targets, so the network degree distribution, average path length, clustering coefficient, and robustness based on PageRank algorithm and permeability-related topological parameters are studied. The research shows that the degree distribution of sandstone pore network satisfies power law distribution, and it can be characterized by scale-free network model. The permeability of rock is inversely proportional to the average path length of sandstone network. The sandstone pore network has strong robustness to random disturbance, while a small number of pores with special topological properties play a key role in the macroscopic permeability of sandstone. This study attempts to provide a new perspective of quantifying the microstructure of the pore network of sandstone and revealing the microscopic structure mechanism of macroscopic permeability of pore rocks.
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Qu, Jun, Qilong Xue, Shixin Bai, and Yazhe Li. "A new type of auxiliary structure for tunnel-surrounding rock support – composite cantilever support structure." Mechanical Sciences 13, no. 1 (2022): 89–99. http://dx.doi.org/10.5194/ms-13-89-2022.
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Abstract. The deformation and damage mechanisms of tunnel-surrounding rock masses have always been a major problem in underground engineering, and studying these mechanisms plays an important role in preventing this kind of geological disaster. Against the background of the above project, in this paper, we propose a new type of support structure: a composite cantilever support structure. Studies involving the numerical calculation and application of this support structure are carried out, and the conducted investigation indicates that (1) for a relatively broken rock mass, the composite cantilever support structure can effectively restrain the deformation of the tunnel-surrounding rock mass, (2) through numerical calculation, the appropriate design parameters of the support structure are obtained, and (3) the design parameters and design structure of the composite cantilever support structure must be further studied and verified under complex geological conditions by engineering.
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Moroz, N. E., D. V. Sidorov, and M. A. Sonnov. "Complex geomechanical modeling of mining vein deposits of block structure." Mining Industry Journal (Gornay Promishlennost), no. 6/2023 (December 25, 2023): 71–74. http://dx.doi.org/10.30686/1609-9192-2023-6-71-74.
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Mining of vein deposits formed in block structures requires consideration of the impact from the deformation processes occurring as a result of changes in the natural and man-induced state of the rock mass. Information on the magnitude and directions of stresses acting in the block mass are the boundary conditions taken into account in further calculations of the stressandstrain state and stability of structural elements of underground geotechnology. For an efficient assessment of the natural stressed state of a tectonically disturbed rock mass, associated with the need for numerical simulation of the geomechanical state of tectonic structures, spread over large areas, the PRESS 3D URAL dedicated software suite (Polygor LLC, St. Petersburg) was adopted for 3D settings. At the same time, due to the occurrence elements and morphology of the ore veins it is advisable to use the CAE Fidesys software suite (Fidesys LLC, Moscow) in 2D settings for local assessment of the stress concentrations in vicinity of mine workings and pillars formed as the result of mining operations.