scholarly journals Substantiation of Safe Conditions During Undermining of Hydraulic Waste Disposal

2018 ◽  
Vol 41 ◽  
pp. 01007
Author(s):  
Yuriy Kutepov ◽  
Aleksandr Mironov ◽  
Maksim Sablin ◽  
Elena Borger

This article considers mining and geological conditions of the site “Blagodatny” of the mine named after A.D. Ruban located underneaththe old open pit coal mine and the hydraulic-mine dump. The potentially dangerous zones in the undermined rock mass have been identified based onthe conditions of formation of water inflow into mine workings. Safe depthof coal seams mining has been calculated depending on the type of water body – the hydraulic-mine dump.

2020 ◽  
Vol 168 ◽  
pp. 00068
Author(s):  
Vasyl Zberovskyi ◽  
Kostiantyn Sofiiskyi ◽  
Rishard Stasevych ◽  
Artem Pazynych ◽  
Jan Pinka ◽  
...  

The paper represents the results of monitoring and evaluation of the efficiency of hydroimpulsive disintegration of outburst-prone coal seams in the stopes of development mine workings using a system of sound detecting facilities. Methods of acoustic emission control have been considered as well as the monitoring tasks to evaluate rock mass conditions before the procedure and after it inclusive of the results of sound accompaniment of hydraulic disintegration of the coal seam. It has been determined that the higher concentration of stresses within the rock mass is, the more efficient action of high frequency self-oscillations of cavitation transmitter is on both the fissuring and changes in gas-dynamic state of the coal seam. It has been recommended to apply a mode of impulsive fluid pumping under the conditions where coal seam is in the stress-strain state.


2019 ◽  
Vol 133 ◽  
pp. 01011
Author(s):  
Jakub Kokowski ◽  
Zbigniew Szreder ◽  
Elżbieta Pilecka

In the study, the determining of the reference velocity of the P-wave in coal seams used in seismic profiling to assess increases and decreases in relative stresses at large depths has been presented. The seismic profiling method proposed by Dubinski in 1989 covers a range of depth up to 970 m. At present, coal seams exploitation in Polish coal mines is conducted at greater depths, even exceeding 1200 m, which creates the necessity for a new reference velocity model. The study presents an empirical mathematical model of the change of the P-wave velocity in coal seams in the geological conditions of the Jastrzebie coal mine. A power model analogous to the Dubinski’s one was elaborated with new constants. The calculations included the results from 35 measurements of seismic profiling carried out in various coal seams of the Jastrzebie mine at depths from 640 to 1200 m. The results obtained cause changes in the result of calculations of seismic anomalies. Future validation of the proposed model with larger data set will be required.


2020 ◽  
Vol 61 (5) ◽  
pp. 71-79
Author(s):  
Hoan Ngoc Do ◽  
Fomin Sergey Igorevic ◽  

In the process of developing the general exploitation and disposal plan for the Deonai, CocSau and Caoson coal mines, use should be taken into account the maximum internal disposal sites to reduce the transport supply and facilitate the environmental restoration work after exploitation. However, in the geological conditions of these coal mines, in order to ensure the space to exploit and make full use of useful minerals, it is necessary to calculate the economic efficiency when building the exploitation and disposal plan. The content of the article is based on the criteria of optimum transportation flows of rock in the arrangement of waste disposal when exploiting a group of three open-pit mines Deo Nai, Coc Sau and Cao Son.


2019 ◽  
Vol 4 (1) ◽  
pp. 57-64
Author(s):  
R. I. Imranov ◽  
E. N. Khmyrova ◽  
O. G. Besimbayeva ◽  
S. P. Olenyuk ◽  
A. Z. Kapasova

The research is aimed at solving problems of assessing underground working stability in complicated mining and geological conditions to increase reliability and safety of mining operations. Analysis of geomechanical processes occurring in a rock mass during extraction of coal seams to determine the stability of mining block roof is the most important task. The performed digital modeling of the rock mass based on the structural logs for K1 seam and the nearest borehole log enabled highly detailed identifying the types of rocks occurred in the seam roof and their strength characteristics, compressive stresses. To determine the stability of a mining block roof, the factor of safety of the rocks was used, which was determined by modeling method using Phase 28.0 and Rockscince software. The carbonaceous argillite parting 0.09–0.12 m thick was taken as the contact of the longwall with the seam roof, and, for completeness of the analysis, the upper high-ash coal member in the seam roof up to 0.7 m thick was used. The modeling findings, presented in the graph of dependence between the safety factor and the distance between the belt heading and air drift, showed that the probability of dome formation in the longwall is high, as the factor of safety of the rocks is less than unity, that indicates the roof instability in the course of the coal seam block extraction. The modeling methods allowed assessing the mine working stability, based on which the measures to improve the reliability and safety of mining operations can be timely developed, and due technical and technological solutions shall be reached.


2021 ◽  
pp. 102-106
Author(s):  
O. A. Isyanov ◽  
◽  
D. I. Ilderov ◽  
V. I. Suprun ◽  
S. A. Radchenko ◽  
...  

Instability of pit wall slopes is the most critical accident in open pit mining. The risk of damages to pit walls is proportional to the height of exposed surfaces and to the time of exposure. Among many factors governing pit wall stability, the major factor is geological structure and weakening zones in rock mass. Deformation processes are initiated in host rock mass of coal seams mostly because of undercutting of weak interlayers. Alongside with local undercutting, another cause of landslides is transition of coal mining from down-dip extraction to up-dip extraction. The sequence of mining and morphology of weak interlayers also have influence on initiation and evolution of deformations. The basic component of engineering solutions on pit wall stability control is optimization of mining sequence and methods of accessing working horizons in open pit mines. Large-scale deformation of Western and Southeastern pit walls in Urtui mine could be avoided using the optimized sequence of mining operations. For example, mining advance mostly along the curve of the Urtui centroclinal fold, with early access and destress of the eastern and, first of all, western wings of the fold could make it possible to evade from up-dip mining of coal seams and, as a consequence, to solve the major geomechanical problems in the open pit mine.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1913
Author(s):  
Marek Cała ◽  
Katarzyna Cyran ◽  
Joanna Jakóbczyk ◽  
Michał Kowalski

The extraction of the Bełchatów lignite deposit located in the vicinity of the Dębina salt dome requires careful planning that considers the influence of mining projects on the slope and salt dome stability conditions. The instability problem is directly related to horizontal and vertical displacement, as well as the complex geological and mining conditions. These conditions are very unique with regard to the co-occurrence of the salt dome and lignite deposits in the same area, as well as the large scale of the pit wall slope. Thus, predicting rock mass behavior and ensuring the safety of mining operations are important issues. The presented analysis focused on the influence of long-term lignite extraction on the western pit wall slope of the Bełchatów field and the salt dome’s stability conditions. This study offers a comprehensive approach to a complex geotechnical problem defined by large-scale, complex geometry, and geological conditions. The rock mass behavior and stress conditions are simulated in numerical modelling. The results of the presented analysis will be useful not only for present mining activities but also for future developments related to post-mining and recultivation plans.


2021 ◽  
Author(s):  
Wu Xiao ◽  
He Ren ◽  
Tao Sui ◽  
Heyu Zhang ◽  
Yanling Zhao ◽  
...  

Abstract Open-pit coal mining has a large impact on land surface, both at the mining pits themselves and at waste sites. After artificial management is stopped, a reclaimed opencast coal mine dump is affected by wind and water erosion from natural processes, resulting in land degradation and even safety incidents. In this paper, the soil erosion and land degradation after 5 years of such natural processes, at the Xilinhot open pit coal mine dump in Inner Mongolia, were investigated. A multi-source data acquisition method was applied: the vegetation coverage index was extracted from GF-1 satellite imagery, high-precision terrain characteristics and the location and degree of soil erosion were obtained using an Unmanned Aerial Vehicle (UAV), and the physical properties of the topsoil were obtained by field sampling. On this basis, the degree and spatial distribution of erosion cracks were identified, and the causes of soil erosion and land degradation were analyzed using a geographical detector. The results show that: 1) The multi-source data acquisition method can provide effective basic data for the quantitative evaluation of the ecological environment at dumps; 2) slope aspect and vegetation fractional coverage are the main factors affecting the degree of degradation and soil erosion. Based on this analysis, several countermeasures are proposed to mitigate land degradation: 1) The windward slope be designed to imitate the natural landform; 2) engineering measures should be applied at the slope to restrain soil erosion; 3) pioneer plants should be widely planted on the platform at the early stage of reclamation.


Author(s):  
B Hussan ◽  
M.I Lozynska ◽  
D.K Takhanov ◽  
A.O Oralbay ◽  
S.L Kuzmin

Purpose. To develop a methodology for assessing the quality of drilling-and-blasting operations when setting the side to the final position. In this regard, it is necessary to study the nature of deformations in the near-side masses of the design open-pit contours and to assess the seismic impact of blast waves in accordance with damage in the near and far zones from the open-pit boundary, as well as the level of generated seismic vibrations. Methodology.A methodology for assessing the quality of drilling-and-blasting operations at the limiting contour of open pits is developed using the analysis of the mining-and-geological conditions of the rocks constituting the field, in-situ surveying of the state of the open-pit sides, analysis of the physical-mechanical properties of the host rocks, analytical studies and instrumental measurements of the blasting effect. Findings.Based on the analytical methods, the calculation and analysis of the seismicity coefficient of the rocks at the field have been performed. By means of instrumental measurement of the blasting effect in open pit, data have been obtained on the seismic impact of blasting operations on the near-side mass. Based on the results of these works, a methodology for assessing drilling-and-blasting operations at the limiting contour of the open pit has been developed. Originality.In this work, to assess the blasting effect, the seismicity coefficient of the rock mass is used, which characterizes the degree of elastic response to external dynamic influence and is a parameter that determines the elastic seismic wave intensity with distance from the site of blasting operations. Based on the calculation, a map of the seismicity coefficient distribution in the open-pit area has been compiled. Using the method of instrumental measurements, which serves to determine the seismic impact of blasting on a rock mass, the degree of blasting effect on a near-side mass has been revealed. This made it possible to develop a method for assessing the blasting quality, based on determining the percentage of permissible deviations in the face drilling quality. Practical value.The results of the work will be used to calculate the safe parameters of conducting the blasting operations when setting the side to the final position. This method for assessing the quality of drilling-and-blasting operations can be applied at any mining enterprise conducting open-cut mining of minerals.


2020 ◽  
Vol 243 ◽  
pp. 293
Author(s):  
Roman Shishkov ◽  
Valerii Fedorin

The article considers one actual method for development coal deposits in the Kuzbass by open-underground mining. The scientific and practical advantages of the proposed method due to the use of common infrastructure of coal mine and a modular mine site (subsequently transformed into a mining and technological structure operating according to the mine – longwall scheme) are presented. Currently, a development strategy for Kuzbass until 2035 has been developed. As part of the strategy, a draft program for subsoil use is being formed in the coal industry department. The program should take into account all the positive and negative aspects associated with coal mining in cities and municipal areas and also their prospects. In the Kuznetsk coal basin, 42 mines and 52 opencast mines are mining, of which 12 enterprises use partially unified infrastructure. According to the results of open-underground mining work conducted by the laboratory of the Institute of Coal and Coal Chemistry of the Siberian Branch of the Russian Academy of Sciences (Institute of Coal SB RAS), the list of sites includes favorable mining and geological conditions with incidence angles of up to 18 degrees. As open-pit coal production increases, many sites encounter such a parameter as maximum allowable (boundary) strip ratio. At the stage of preparing the feasibility study for the development of a coal deposit, this coefficient is calculated first of all, since duration of enterprise’s work and its economic component depend on it. In order to increase parameters, it is necessary to carry out transition from open works to underground. As a result, coal mine will not work at a loss, providing production with an economically disadvantageous strip ratio.


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