The influence of rigidity of the collapsed roof rocks in the mined-out space on the state of the preparatory mine workings

The mining industry is fundamental in the violation of the natural environment and the creation of technogenic. Due to the fact that the natural, disturbed and technogenic environments are in direct contact with each other, there are a number of interrelations between them that affect the general state of the environment. It is shown that the interaction of disturbed and technogenic arrays with the natural geological environment leads to the development of negative processes in the form of landslides, flooding and drainage of territories. In turn, these negative processes lead to the formation of secondary disturbances in the natural environment and directly in disturbed and technogenic arrays - additional sedimentation and deformation of rocks, the formation of dips. The main reason for the development of such hazardous processes is the violation of the hydrogeological regime in the vast territories adjacent to the mine workings. Studies of the hydrogeological and hydrological regimes in disturbed and technogenic arrays are given. The processes of landslide formation and their causes in quarries and in dumps of enterprises mining various types of minerals are considered.

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Use of ultrasound to determine the state of the roof rocks of mining-out rooms

Soviet Mining Science ◽

10.1007/bf02497846 ◽

1972 ◽

Vol 8 (4) ◽

pp. 371-377 ◽

Cited By ~ 1

Author(s):

O. A. Baikonurov ◽

T. M. Ermekov

Keyword(s):

The State ◽

Roof Rocks

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Development and testing of an algorithm for calculating the load on support of mine workings

Mining of Mineral Deposits ◽

10.33271/mining15.01.001 ◽

2021 ◽

Vol 15 (1) ◽

pp. 1-10

Author(s):

Volodymyr Bondarenko ◽

Iryna Kovalevska ◽

Frederick Cawood ◽

Oleksandr Husiev ◽

Vasyl Snihur ◽

...

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Support System ◽

Mine Working ◽

Strain State ◽

The Finite Element Method ◽

Load Bearing ◽

Geological Conditions ◽

Mine Workings ◽

Roof Rocks

Purpose. The purpose is to develop the calculation methods for minimizing the load on the fastening system of the preparatory mine working in difficult mining and geological conditions of its maintenance. Methods. By analysing the multivariate computational experiments on the study of the stress-strain state of the load-bearing elements of the ‘massif – support’ system in the preparatory mine workings by means of the finite-element method, as well as mine observations and measurements of displacement in the coal-overlaying rock formation. Findings. An algorithm has been developed for searching the rational modes of the fastening system resistance and methods for minimizing the load on the support of the preparatory mine working, maintained in very complex mining and geological conditions. Originality.The methodical principles have been developed of minimizing the load on the fastening system of the preparatory mine working, which are based on the use of a combination of stress-strain state studies of the ‘massif – support’ system by means of the finite element method and provisions of normative documents for calculating the dimensions of the dome of natural equilibrium of the mine working roof rocks. Practical implications. The operation modes optimisation of the load-bearing elements interaction of the mine working fastening system reduces the material and labour costs during its construction and increases its stability during operation. Keywords: analysis, calculation, optimization, support, preparatory mine working, stope works, roof rocks, collapse

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INFLUENCE OF UNDERMINING ROCK MASS ON THE STATE OF MINE WORKINGS

SCIENTIFIC PAPERS OF DONNTU Series: “The Mining and Geology” ◽

10.31474/2073-9575-2021-1(25)-2(26)-64-72 ◽

2021 ◽

pp. 64-72

Author(s):

Boris Kodunov ◽

◽

Alexander Nosach ◽

Keyword(s):

Computer Simulation ◽

Rock Mass ◽

Mine Working ◽

Simulation Method ◽

The State ◽

Practical Significance ◽

Electric Locomotive ◽

Subsidence Trough ◽

Significant Deterioration ◽

Mine Workings

Purpose. Research of influence of shifts of rocks on a condition of mine workings at their undermining by longwalls. Methods. The study used a computer simulation method. The simulation was performed by simulating the process of rock shift. The initial coordinates of the points of the rock mass turned into the final ones. This allowed to build sections of the rock mass after undermining, which characterized its deformed state, as well as graphs of displacements and deformations in the mine workings. Results. The performed simulation showed that during the movement of the longwall, the mine working (drift), which is undermined, consistently falls into the zone of horizontal deformations of tension, compression and complete displacements. After stopping the longwall, part of the mine working near the boundaries of the displacement area will be constantly in the zones of stretching and compression. It is established that at a distance of 40 m in front of the moving face, the mine working is in the least favorable conditions with maximum vertical compression deformations. Under the given conditions the drift for the most part after completion of clearing works is in a zone of full subsidence. This zone is characterized by the maximum possible subsidence and the absence of deformations. The performed researchers showed that the conditions of undermining of the southern field haulage drift of seam l7 proved to be quite favorable. Shifts and deformations did not cause a significant deterioration in the state of mine working, except for the increase of slopes on the edge sections of the subsidence trough, which makes it difficult to carry out electric locomotive rolling. For any other purpose, after minor repairs, the mine working may continue to operate. Scientific novelty. The study of the process of shear by computer simulation allowed to establish the patterns of shear and deformation during undermining of the mine working. This is the first time for the conditions of the Ukrainian Donbass. Practical significance. The obtained results can be used to predict the condition of mine workings that are undermined during the cleaning works in similar conditions. Key words: undermining overlying mine workings, shifts, deformations, zone of full subsidence, subsidence trough.

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DETERMINING THE PATTERNS OF STABILITY OF MINE WORKINGS FOR CALCULATION ROOF BOLTING PARAMETERS

Geoengineering ◽

10.20535/2707-2096.6.2021.241795 ◽

2021 ◽

pp. 9-16

Author(s):

S. Barsukov ◽

А.Т. Batyrkhanova ◽

Vladimir Dyomin

Keyword(s):

Coal Seam ◽

Longwall Mining ◽

Practical Significance ◽

Roof Bolting ◽

Pull Out ◽

Deformation Processes ◽

Mine Workings ◽

The Stability ◽

Host Rocks ◽

Roof Rocks

Purpose. The published studies are aimed at determining the mechanism of deformation of the rocks of the contour around the workings in terms of the parameters of the emerging fracturing and their dependence on the indicators of the strength of the rocks and the depth of occurrence in the massif. The tasks of the study include the installation of fracture indicators, the determination of the parameters of the development of the deformation process around the working, including the effect of longwall mining and taking into account the possibility of reuse of the workings. Methodology. To solve the set tasks, the method of field observations was used together with the use of regression dependencies to determine the dependences of the parameters on the influencing factors. In addition, the method of full-scale pull-out tests of anchor support was used, which made it possible to determine the clamping forces of the anchors. Originality. In the course of the research, the dependences of stresses and deformation along the K7 coal seam in the conditions of the mine named after Kuzembaev CD JSC "ArcelorMittal Temirtau" for the massif around the mine with fastening. Rational parameters for the use of roof bolting in preparatory mine workings have been established. This type of fastening provides direct contact between rocks and lining. Analysis of the results of calculating the parameters of the roof bolting showed that to maintain the roof in the development workings, it is necessary to take into account the parameters of the roof bolting. The main parameters include the length of the anchors, the total resistance of the roof bolting and the density of the anchors. Anchor support forms laminated rock beams in the roof rocks, which ensure the stability of the workings. Conclusions and practical significance. The results of studies devoted to the establishment of the influence of mining-geological and mining-technical factors on the formation of zones of inelastic deformation in the host rocks were considered. Significant dependences of the deformation processes of rocks in the massif around the workings were obtained, and the parabolic zone of destruction of rocks was determined. The practical significance of the research consists in determining the actual indicators of the required bearing capacity of the anchorage at two levels in the conditions of the development of the coal seam k7 of the Kuzembaev mine.

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Experimental Studies about Characteristics of the Rocks Displacement and State of Bearing Pressure on the Haulage Roadway

E3S Web of Conferences ◽

10.1051/e3sconf/201910501008 ◽

2019 ◽

Vol 105 ◽

pp. 01008

Author(s):

Duc Thang Pham ◽

Hung Thang Hoang ◽

Victor Vitcalov

Keyword(s):

Rock Pressure ◽

Roof Rock ◽

Experimental Studies ◽

Coal Seams ◽

Coal Basin ◽

Mining Depth ◽

The Face ◽

Mine Workings ◽

Roof Rocks ◽

Quang Ninh

Comprehensive studies were conducted using measuring stations to measure the rock pressure and displacements of the roof rocks in the mine workings adjacent to the face when extracting medium thick inclined coal seams with the use of longwall (seam 6 at the Quang Hanh mine of Quang Ninh coal basin, Vietnam). The results of the study show that the displacement of the roof rock on the parallel roadway increases sharply at a distance of 1 to 12 m to the face, varies from 20 to 40 mm when the mining depth of the coal seam is 200 m and the maximum rock pressure on the haulage roadway supports is located at a distance of 3–8 m ahead of the face and is from 14 to 16 tons ranges.

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