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Date submitted2022-10-29
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Date accepted2023-10-25
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Date published2024-04-25
Assessment of rock massif sustainability in the area of the underground research laboratory (Nizhnekanskii Massif, Enisei site)
The study presents the results of the research on geodynamic and geological conditions of the Enisei site (Krasnoyarsk Krai), chosen for the construction of an underground research laboratory. The laboratory is being built at a depth of 500 m to assess the suitability of the rock mass for burying high-level radioactive waste. The rocks consist of weakly fractured gneisses, granites, and dikes of metadolerites. Field observations were conducted on bedrock outcrops. They included the determination of rock mass quality indicators, measurement of rock fracturing, and a rating classification of stability using N.Barton's method. GNSS observations were also made to monitor surface deformations. These data were used to develop a three-dimensional structural model, including lithology, fault disruptions, intrusive bodies, elastic-strength properties of rocks, and the sizes of zones influenced by faulting. It will serve as a basis for boundary conditions and the construction of three-dimensional variational models of stress-strain states, identifying zones of concentration of hazardous stresses, and planning in situ geomechanical experiments in underground mines of the laboratory. The obtained values of the modified QR index for the main types of rocks allowed their classification as stable and moderately stable, corresponding to strong and very strong rocks on Barton's scale and the massif rating according to geomechanical classification.
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Date submitted2021-01-19
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Date accepted2021-07-27
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Date published2021-10-21
Geological and structural characteristics of deep-level rock mass of the Udachnaya pipe deposit
- Authors:
- Evgenii V. Serebryakov
- Andrei S. Gladkov
For hard rock massifs, structural disturbance is a key indicator of mining structure stability. The presence of intersecting structural elements in the massif reduces rock strength and leads to formation of potential collapse structures. In addition to that, disjunctive deformations that penetrate rock strata serve as channels for fluid migration and connect aquifers into a single system. It was established that the largest of them –faults of east-northeastern, northeastern and northwestern directions – form the kimberlite-bearing junction of the Udachnaya pipe. These faults represent zones of increased fracturing, brecciation and tectonic foliation, distinguished from adjacent areas by increased destruction of the rock mass. Specifics of tectonic fracture distribution within structural and lithological domains are determined by the presence of multidirectional prevailing systems of tectonic fracturing, as well as by differences in their quantitative characteristics. With some exceptions, the main systems form a diagonal network of fractures (northeastern – northwestern orientation), which is typical for larger structural forms – faults. Despite the differences in dip orientation of the systems, most of them correspond to identified directions, which is typical for both kimberlites and sedimentary strata. Overall disturbance of the massif, expressed in terms of elementary block volume, reaches its peak in the western ore body. For such type of deposits, friction properties of fracture structures have average values. Consideration of geological and structural data in the design and development of new levels of the deposit will allow to maintain the necessary balance between efficiency and safety of performed operations.
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Date submitted2019-02-01
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Date accepted2019-09-16
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Date published2020-02-25
Priority parameters of physical processes in a rock mass when determining the safety of radioactive waste disposal
- Authors:
- V. S. Gupalo
Consideration of geodynamic, hydrogeochemical, erosion and other quantitative characteristics describing evolutionary processes in a rock mass is carried out when choosing a geological formation for the disposal of radioactive waste. However, the role of various process parameters is not equal for safety ensuring and additional percentages of measurement accuracy are far from always being of fundamental importance. This makes it necessary to identify various types of indicators of the geological environment that determine the safety of radioactive waste disposal for their detailed study in the conditions of the burial site. An approach is proposed to determine the priority indicators of physical processes in the rock mass that determine the safety of disposal of various types of radio active waste and require increased attention (accuracy, frequency of measurements) when determining in - situ conditions. To identify such factors, we used the sensitivity analysis method that is a system change in the limits of variable values during securty modeling in order to assess their impact on the final result and determine the role of various physical processes in ensuring safety.
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Date submitted2014-07-12
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Date accepted2014-08-24
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Date published2014-12-22
The study of structural features of outburst coal seams
- Authors:
- V. N. Zakharov
- O. N. Malinnikova
A study of the structural features of outburst-dangerous and non-outburst dangerous coal layers was conducted. It was shown that coal taken from a sudden outburst zone has a significantly greater sorption surface than coal from the same layer which was not part of the sudden outburst. The size of the sorption surface of coal is affected by its history up to that point; thus the heating of the coal sample during its preparation enlarges its sorption surface. An electron microscope study of coal surfaces has shown that for coal from outburst-dangerous layers, a disturbed structure with a large quantity of fissures and partings the size of 1 micrometer is typical. Under the same enlargement, a coal structure from safe coal layers is much more uniform. The study of digital images of coal surfaces, taken with the help of an electron microscope, shows that the structural institution of surface elements may be presented by multifractal analysis, with its spectrum of fractal dimensions, which allows us to state quantitative distinctions in coal microstructures for outburst-dangerous layers. Coal from outburst-dangerous layers has a greater set of structural elements, and therefore a spectrum of fractal dimensions that is 1.5-2 times wider than for nonoutburst dangerous layers.
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Date submitted2009-10-18
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Date accepted2009-12-17
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Date published2010-09-22
Reuse of development workings as an element of providing the effective coal output
- Authors:
- M. A. Ilyashov
The article contains the results of application in a coal mine of a combined way for protection and support of development workings. This method combines a frame support, anchors and a cast support strip erected behind the longwale. The geomechanical substantiation of technological parameters, regulations and the field for efficient use of this method are given. Its introduction has allowed to increase the loads on longwale and to lower labour content and expenses for maintenance of butt entries.
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Date submitted2009-10-05
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Date accepted2009-12-05
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Date published2010-09-22
Control of rock mass state in mining the sections at mines оf the Vorkutaugol JST: up-to-date practice
- Authors:
- O. V. Yamenko
- I. E. Plisko
The article briefly outlines the methods and measures used at mines of the Vorkutaugol JSC to control the stress strain state of rock massif. These measures help to increase face load and to ensure mine safety.
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Date submitted2009-07-21
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Date accepted2009-09-27
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Date published2010-04-22
Study of gas-and geodynamic state of technogenically changeable coal rock mass
- Authors:
- A. D. Ruban
Intensification and concentration of the mining works increases substantially the risk of geo- and gasdynamic effects arising within the coal mines. Herewith are presented the results of the analytic and experimental studies on stress-strain state of rock mass due to technogenic impact. Under such conditions a potential avalanche destruction of coal rock mass may occur. Some criteria for evaluation of gas-dynamic danger for rock mass, for active stopes and development faces are given. The computer-aided system for monitoring of hazard of gas- and geodynamic phenomena in mines is suggested.
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Date submitted2009-07-05
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Date accepted2009-09-27
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Date published2010-04-22
The methods of strength definition for the rock mass properties applying to the open mining cut
- Authors:
- A. A. Pavlovich
The review of factors influencing rock mass strength is given. Methods of definition for sample strength changeover to rock mass are considered in the article.