scholarly journals Technical and technological aspects of the coal mine closure based on the geomechanical component assessment

2021 ◽  
Vol 15 (3) ◽  
pp. 7-15
Author(s):  
Mykhailo Barabash ◽  
Ildar Salieiev ◽  
Hennadii Symanovych

Purpose.Development of a comprehensive methodology for assessing the state of mine workings based on the analysis of their contour displacement patterns when solving the problem of minimizing the risks during the closure of coal mines in Ukraine. Methods. Based on an integrated analysis of international and domestic trends when assessing the consequences of mine closure, the main provisions of using the method of instrumental mine observations have been substantiated. When solving the problem, the approaches of regulatory documents are taken into account to identify the geomechanical situation according to two conditions: the structure and strength properties of the lithotypes in the adjacent coal-bearing stratum and the peculiarities of the rheological processes manifestation during the development of its displacements. Findings. The geomechanical, technological and hydrogeological factors have been distinguished that are required to take into account when closing the coal mines. Fundamental methodological provisions have been substantiated for the most reliable assessment of the mine workings state, taking into account the long period of their operation. A criterion for making a decision on the decommissioning of mine workings or their further maintenance is presented. Originality.A series of generalizing dependences of the mine working contour displacement development has been obtained, which can be divided into four main groups according to the criteria of the structural and strength properties of lithotypes in the adjacent mass, as well as the type of their rheological manifestations: decaying and persistent deformation creep. For each group, using the methods of correlation-dispersive analysis, empirical formulas have been determined for calculating the convergence of the roof and bottom of mine workings, as well as their sides, depending on the geomechanical criterion H/R of the maintenance conditions and the duration t of this period. Practical implications.The obtained correlation ratios make it possible to predict the residual section of mine working at any time of its maintenance. They are a geomechanical component of its operational state assessment. The result of this research is the development of a new methodology for assessing the mine working state according to the patterns for predicting its contour displacement.


Author(s):  
I.A. Salieiev ◽  
V.I Bondarenko ◽  
H.A Symanovych ◽  
I.A Kovalevska

Purpose. Substantiation of the methodology for predicting the state of mine workings based on the study on geomechanical processes when assessing the consequences of mine closure taking into account the entire period of their existence, during which the development of displacement with various intensity occurs in the surrounding coal-bearing mass. Methodology. The study is based on methods of analysis and synthesis, methods of comparison, abstraction, analogy, calculation and construction. The methods of mine tool observations of the manifestations of rock pressure and their processing by methods of correlation and dispersion analysis for establishing the relationship of displacements of the mine working contour with geomechanical factors were used. Findings. A possibility of stage-by-stage decommissioning of mine workings when grouping mining-and-geological conditions is substantiated. An example of calculating the displacements in a mine working during its decommissioning is presented. The given calculation expressions make it possible to assess the mine working state, taking into consideration the patterns of the geomechanical factor influence on making a technical decision on the expediency of its further operation. Originality. The patterns of the rock pressure manifestation development in sequentially abandoned mine workings have been determined. Based on the methods of correlation-dispersion analysis, the dependence of the mine working contour displacements on geomechanical factors have been revealed throughout the entire period of its existence. Practical value. A methodology for assessing the state of mine workings at the time of their decommissioning has been developed, which is an integral part of the recommendations to limit the negative influence of mine closure. The peculiarity of the methodology is in taking into account the entire period of mine workings existence, which leads to a well-grounded technical decision on the possibility of dismantling the metal structures with the complete exclusion of emergency situations.



Author(s):  
Demin Vladimir, ◽  
◽  
Mussin Ravil, ◽  
Demina Tatiana, ◽  
Zhumabekova Aila, ◽  
...  

To achieve the objective with the claimed technical result, a method of fastening mine workings of predominantly rectangular cross-sectional shape with anchor bolts was used, while the applied task of reducing the heaving of soil rocks is to increase the efficiency of mine workings by ensuring that the mine workings. Ensuring the possibility of reliable and of good quality fortified rocks along the contour of making within the boundaries of the zone of possible collapse of rocks. The length of the soil anchors did not significantly affect the condition of the soil rocks. Consequently, that on the deformations and stresses both in the lateral and in the soils are not soil, but lateral anchors. The use of these technological developments will reduce the cost of conducting and maintaining workings by 7–10% with soil anchors (reducing maintenance costs by 7–10%) and will provide an economic effect of 10–15 thousand tenge per running meter of output.



2021 ◽  
Vol 15 (4) ◽  
pp. 130-138
Author(s):  
Olena Zavialova ◽  
Viktor Kostenko ◽  
Natalia Liashok ◽  
Mykola Grygorian ◽  
Tetiana Kostenko ◽  
...  

Purpose. Assessing the process of damaging factors formation during the coal aerosol explosion in mine workings on the basis of theoretical research of the explosion of coal dust deposits in order to substantiate promising methods of protecting miners from their impact. Methods. An integrated approach is used, which includes a critical analysis of literature data on the occurrence and development of coal aerosol explosions in mine workings; theoretical research into the state of the gaseous medium at the characteristic points of the development diagram of the coal dust deposits explosion as a result of mining operations based on the laws of classical physics and chemistry. Findings. The main aspects of the explosion mechanism of dust in a powdery state, accumulated on the surfaces along the mine working perimeter, and the formation of such negative factors as the effect of gaseous medium accelerated movement, have been revealed; high temperature formed during coal and methane detonative combustion; increased gas pressure. The revealed aspects of the dust explosion mechanism make it possible to determine the main directions for protection of miners caught in the explosion. The diagram of the development of settled coal dust explosion along the mine working with normal ventilation conditions, taking into account the influence of seismic waves, has been improved. Originality. Analytical dependences, reflecting the value of gas energy at characteristic points of the diagram, have been determined, and the dynamics of the formation of negative factors caused by the explosion have been revealed. Practical implications. Possible ways of protecting miners from the impact of negative factors caused by the coal aerosol explosion and reducing the severe consequences of such accidents are proposed.



2018 ◽  
Vol 277 ◽  
pp. 157-167 ◽  
Author(s):  
Oleh Khomenko ◽  
Maksym Kononenko ◽  
Janchiv Bilegsaikhan

The first classificationsw of physical properties of rocks and hypotheses of rock pressure in the world practice are analysed. The analysis of internationally widely known theories about rock pressure and physical processes around mine workings is executed. Classification of theories about rock pressure on classification feature “condition of investigated massif” is constructed. The energy theory that describing capsulation by the massif of underground mine working is offered.



2019 ◽  
Vol 123 ◽  
pp. 01006 ◽  
Author(s):  
Iryna Kovalevska ◽  
Zenon Pilecki ◽  
Oleksandr Husiev ◽  
Vasyl Snihur

The degree of influence has been determined of diversified deformation-strength characteristics of load-bearing elements in the fastening system of the preparatory mine workings, while maintaining them in a laminal massif of soft rocks. The analysis has been performed of multivariate computational experiments of the stress-strain state of the load-bearing elements of the fastening system in the preparatory mine workings from the position of the mutual influence of their deformation-strength characteristics and the support loading as a whole. An analysis is represented of the mutual influence of the operation modes of the mine working support elements between themselves and the fastening system as a whole; it has been studied the stress-strain state of the mine working fastening system with a central hydraulic prop stay, as well as a significant increase in reliability of the support performance has been analysed and determined. The tendency has been substantiated of minimizing the load on the mine working fastening system – increasing the coherence of the diversified operation modes of fastening elements by enhancing preferentially the yielding property of the rigid element. The application has been substantiated of the central yielding prop stays of the strengthening support of a frame in case of intensive rock pressure manifestation in the zone of the stope works active influence.



Ugol ◽  
2018 ◽  
pp. 44-49 ◽  
Author(s):  
S.V. Cherdantsev ◽  
◽  
Kh.U. Lee ◽  
Yu.M. Filatov ◽  
P.A. Shlapakov ◽  
...  


2019 ◽  
Vol 59 (4) ◽  
pp. 539-545
Author(s):  
O. M. Andreev ◽  
D. V. Drabenko ◽  
R. A. Vinogradov ◽  
E. U. Orlova

The article presents results of investigation of the climate warming effects in the northern polar region of the Earth, in particular on some characteristics of ice in the northern part of the Ob Bay (the area of the most active economic activity of the Russian Federation in the last decade). It is determined that over the past 40 years, morphometric and strength characteristics of ice have significantly changed. Estimates of ice thickness obtained using simple empirical formulas (depending on the sum of the degree-days of frost) show that the ice thickness decreased here by an average of 10 15%. The strength characteristics of ice were analyzed for two periods: the maximum strength of ice (for this area it is March) and the maximum development of ice thickness (usually it is May). It was found that the strength properties of ice (bending and compression) for both periods decreased by 10-12%. Thus, in recent decades, under the influence of climate warming in the Ob Bay, the thickness and strength of the ice cover have significantly decreased. This circumstance will be favorable for further development of the considered water area by Russian oil and gas companies.



2019 ◽  
Vol 3 (180) ◽  
pp. 41-51
Author(s):  
Viacheslav Lukinov ◽  
Kostiantyn Bezruchko ◽  
Mykhailo Matrofailo ◽  
Liubov Kuznetsova

Sudden coal and gas outbursts in coal mines are one of the most harmful and at the same time, dangerous gas-dynamic phenomena faced when coal producting. The sudden coal and gas outbursts is the evanescent destruction of the bottom-hole area in the coal bed, which develops from the bottom into the depth of a massif, and the crushed coal with gas is thrown to a long distance from the bottom into the mine, destroying everything in its way, creating the conditions for explosion and fire breaking-out. Sudden outbursts lead to significant material losses for the recovery from an accident and in some cases injuries and human losses. The problem of reliable prediction, prevention, and control of sudden coal and gas outbursts at coal mines remains extremely urgent, due to the constant increase in the depth of mining operations. The analysis of the experience of predicting and preventing the outburst hazard in coal beds of Donets and Lviv-Volyn coal basins is analyzed. At Donbas mines since 1906, there have been more than 7.5 thousand sudden outbursts. Although mining had now reached considerable depths (from 300 to 600 m), the emergence of coal and gas outbursts have not been recorded. The purpose of the research is to determine the depth of the possible emergence of sudden coal and gas outbursts in the LVB, with regard to the peculiarities of the geological structure of the coal-bearing strata in the Lviv-Volyn coal basin. The comparative possible depth estimation in the manifestation of the outburst hazard of the coal beds in the LVB is given. It is calculated according to the normative technique and performed according to the formulas obtained by the statistical analysis for the actual position of the minimum depth of coal and gas outbursts at the Donbas mines. The absence of sudden coal and gas outbursts at LVB mines on the coal beds, which are hazardous according to the prediction data, is performed according to the methods regulated by the normative documents and compiled by the experience of studying the outbursts in Donbas, is explained by the differences in the geological structure of the LVB, the main of which is the presence of thick mass of covering deposits and a significantly greater depth of the methane gas zone. The application of the empirical formulas prediction, which includes the methane gas zone depth index, allows us to account for these differences and it is much more reliable to determine the possible depths of sudden outbursts for LVB, which, all other things being equal, should be greater than in the Donbas. In particular, according to the performed calculations, the outburst hazard situation at the “Stepova” mine is predicted at depths of more than 700 m. As prediction indices for the calculations, values of methane gas zone depths of 450 m were adopted, and the minimum value of volatile-matter yield was 33.3%. This approach can be proposed for predicting the coal and gas outbursts hazard in other Lviv-Volyn basin mines. To determine the predicted depth of the possible emergence of sudden coal and gas outbursts, it is advisable to take into account the depth of the methane gas zone in the prediction calculations.



2017 ◽  
Vol 25 ◽  
pp. 171-178
Author(s):  
Roman Tereshchuk ◽  
Oleksii Hryhoriev

Determination of rational values of curvature radii of roof beam and stands to solve the problem of selecting rational shape of metallic frame flexible support under various mining and geological conditions of coal mines. The necessity to solve the problem of the determination of rational shape of metallic flexible support has been substantiated. Methodology to solve the problem of improving metallic frame support with the help of analytic equations of structural mechanics is represented. Shapes of mine working cross-sections as well as metallic support depending upon coefficient of lateral spreading obtained as the calculation results have been obtained. Further tendencies in research to improve mine working support have been determined.



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