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Date submitted2021-10-31
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Date accepted2023-03-02
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Date published2023-12-25
Improvement of technological schemes of mining of coal seams prone to spontaneous combustion and rock bumps
On the example of the Alardinskaya mine, the problem of underground mining of seams prone to spontaneous combustion and rock bumps in the conditions of the Kondomsky geological and economic region of the Kuznetsk coal basin is considered. The contradictions in the requirements of regulatory documents for the width of the inter-panel coal pillars in the mining of seams with longwalls in conditions of endogenous fire hazard and in the mining of seams that are dangerous due to geodynamical phenomena are discussed. These contradictions impede the safe mining of seams using traditionally used layouts with the danger of spontaneous combustion of coal and rock bumps. A mining-geomechanical model is presented, which is used for numerical three-dimensional simulation of the stress-strain state of a rock mass with various layouts for longwall panels using the finite element method. The results of the numerical analysis of the stress state of the rock mass immediately before the rock bump are presented, and the main factors that contributed to its occurrence during the mining of the seam are established. A dangerous degree of stress concentration in the coal seam near the leading diagonal entries is shown, especially in conditions of application of abutment pressure from the edge of panels’ gob. The analysis of the features of stress distribution in the inter-panel pillar at different widths is carried out. Recommendations for improving the layout for the development and mining of coal seams that are prone to spontaneous combustion and dangerous in terms of rock bumps in the conditions of Alardiskaya mine have been developed. The need for further studies of the influence of pillars for various purposes, formed during the mining of adjacent seams, on the stress-strain state of previously overmined and undermined seams is shown.
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Date submitted2018-11-03
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Date accepted2019-01-21
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Date published2019-04-23
Estimation of critical depth of deposits by rock bump hazard condition
- Authors:
- V. N. Tyupin
During the development of minerals by the underground method, dynamic manifestations of rock pressure occur at a certain depth, which significantly reduces the safety of mining operations. Regulatory documents prescribe at the exploration and design stages to establish the critical depth for classifying a deposit as liable to rock bumps. Currently, there are a number, mainly instrumental, methods for determining the liability of rock mass to rock bumps and methods based on the determination of physical and technical properties and the stress-strain state of rock massifs. The paper proposes a theoretical method for determining the critical depth for classifying a deposit as liable to rock bumps. A formula for determining the critical depth of the rock bump hazard condition is obtained. A mathematical analysis of the influence of the physical and technical parameters of the formula on the critical depth is carried out. Its physical and mathematical validity is substantiated. The numerical calculations of the critical depth for 17 developed fields were carried out using a simplified formula. It also provides a comparison of calculated and actual critical depth values. It is established that the variation of the actual and calculated critical depth is due to the lack of actual data on the value of the friction coefficient and parameters of fracturing of the rock mass in the simplified formula. A simplified calculation formula can be used to estimate the critical depth of a field at the survey and design stages. More accurate results can be obtained if there are actual data on fracture parameters, friction coefficients and stress concentration near the working areas.
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Date submitted2014-11-05
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Date accepted2015-01-24
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Date published2015-10-26
Use of geoinformation technologies for otpimized distribution of stations of atmospheric air quality monitoring
- Authors:
- M. V. Volkodaeva
The article deals with possible applications of modern geographic information systems for optimized distribution of stations of atmospheric air quality monitoring. Due to the fact that estimation of atmospheric pollutant concentrations is a reason for decisions to improve air quality, costly measures to protect the atmosphere and monitoring effectiveness of these actions, atmospheric air quality indicators, and therefore the proper distribution of monitoring stations, are of great importance. Results of model calculations of atmospheric air pollution, which have been recently developed in our country, in combination with GIS solutions, should be used for optimized distribution of stations of atmospheric air quality monitoring. One of the major factors of objective estimation of urban atmospheric air quality is proper reference of industrial and transport pollutant emission sources to the city’s topographic base (both in citywide and local coordinate systems), as well as distribution of stations of atmospheric air quality monitoring and selection of high-priority pollutants for a particular city district. Some recommendations for monitoring stations distribution and pollutants selection based on the GIS analysis of spatial distribution of maximum ground level concentrations of pollutants are given.
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Date submitted2014-07-21
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Date accepted2014-09-19
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Date published2014-12-22
Preliminary preparation of oil for primary processing
Oil supplied for primary processing always undergoes preliminary preparation, the purpose of which is to eliminate the harmful effect of water and salt contained in the oil. It is thought that corrosion of the equipment is connected mainly with chlorides of magnesium and calcium, which are subjected to hydrolysis with the formation of hydrochloric acid. Under the influence of hydrochloric acid the destruction (corrosion) of metal equipment at technological plants occurs (especially refrigerating-condensing and heatexchange equipment, furnaces of rectification units etc.). The authors of the article, on the basis of thermodynamic calculations, provide their point of view on this process and give a methodology by which the process of preliminary oil dehydration and desalting can be controlled. The thermodynamic calculations executed for standard conditions on the basis of refer-enced data confirm a high probability of chemical interaction of iron with hydrogen ions, hy-drogen sulphide and especially with carbonic acid. This testifies to high activity of the carbon dioxide dissolved in water and the impossibility of hydrolysis of ions of magnesium, calcium and iron. The calculations show that only the hydrolysis of magnesium chloride is possible tak-ing into account the ionic composition of the water phase in the oil. It should be noted that the presence of ions of chlorine shifts the iron potential in a nega-tive direction and increases the speed of corrosion of petrochemical equipment. The solution of this problem is in the development of modern methods of crude oil dehydration and desalting. It is also, however, in an intensification of the processes of mixing water-oil emulsions with wash-ing water by using various physical fields (for example, ultrasound) and creating new effective mixing devices on the basis of them.
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Date submitted2013-07-11
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Date accepted2013-09-05
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Date published2014-03-17
Mathematical modelling of applied problems of rock mechanics and rock massifs
- Authors:
- A. P. Gospodarikov
- M. A. Zatsepin
The variety of the mining and geological conditions with further increasing in depth of the development of bedded deposits leads to necessity for the analysis of stress and strain state near different types of excavations.
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Date submitted2009-10-15
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Date accepted2009-12-30
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Date published2010-09-22
Geotechnical monitoring in cryolite zone. Ecological or industrial safety
- Authors:
- A. P. Popov
The article contains the principal methodological points of the technology of geotechnical monitoring of engineer constructions in the cryolite zone. By way of practical example it was shown the efficiency of its application for reduction of risks in the industrial and economic activities of Gasprom Co by means of creation of numerical models of stability of ground basements and foundations, timely control of mechanical safety of buildings and constructions, qualitative substantiated numerical forecasting and potential variant modeling of aftereffects of technical decisions for stabilization of a situation. Geotechnical monitoring in contrast to the industrial production ecological monitoring is the technology for control of mechanical safety of buildings and constructions at the stages of their designing, construction and exploitation.
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Date submitted2009-09-15
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Date accepted2009-11-02
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Date published2010-06-25
Mathematical modeling of stress-strain state of the mined seam deposits
- Authors:
- A. P. Gospodarikov
- M. A. Zatsepin
Development of bedded deposits is associated with man-caused distortion of specific environment – the rock massifs, which are very complicated in their composition, can vary significantly in mechanical properties and is characterized with a wide variety of laws and techniques to assess its stress-strain state.
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Date submitted2009-09-19
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Date accepted2009-11-24
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Date published2010-06-25
The forecast of the stress-strain state of massifs rocks in the bed deposits
- Authors:
- A. P. Gospodarikov
- M. A. Zatsepin
The variety of the mining and geological conditions with further increasing in depth of the development of bedded deposits leads to necessity for the analysis of stress-strain state near different types of excavations.
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Date submitted2009-07-16
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Date accepted2009-09-28
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Date published2010-04-22
Efficient numerical methods for geotechnical problems
- Authors:
- M. A. Karasev
This article give a general overview of methods to solve large scale geotechnical problems, nonlinear high deformation and plastic problems, self contact of strata and application of high performance computing.