Analysis of Rock Pressure Manifestation in the Preparatory Mine Workings at the Structural Transformation of Enclosing Rocks by the Roof-Bolt Strengthening

2020 ◽  
pp. 6-16
Author(s):  
V. Bondarenko ◽  
I. Kovalevska ◽  
H. Symanovych ◽  
M. Barabash ◽  
V. Chervatiuk ◽  
...  
Keyword(s):  
Structural Transformation ◽  
Rock Pressure ◽  
Roof Bolt ◽  
Mine Workings ◽  
Enclosing Rocks

scholarly journals Classification of Theories about Rock Pressure

2018 ◽  
Vol 277 ◽  
pp. 157-167 ◽  
Author(s):  
Oleh Khomenko ◽  
Maksym Kononenko ◽  
Janchiv Bilegsaikhan
Keyword(s):  
Physical Properties ◽  
Rock Pressure ◽  
Mine Working ◽  
Physical Processes ◽  
Classification Feature ◽  
The World ◽  
Underground Mine Working ◽  
Mine Workings ◽  
Energy Theory

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.

Evaluation of the influence of aerodynamic aging of production on aerological risks on coal mines

2020 ◽  
pp. 74-83 ◽  
Author(s):  
O. V. Skopintseva ◽  
S. V. Balovtsev
Keyword(s):  
Rock Pressure ◽  
Average Rate ◽  
Coal Mines ◽  
Entire Period ◽  
Risk Indicator ◽  
Average Value ◽  
Rate Of Increase ◽  
Mine Workings ◽  
Aging Factor

The results of a study of the aerodynamic aging of mine workings are presented. It is established that the local workings located in the zone of active manifestation of rock pressure are most deformed. The average rate of increase in their resistance reaches 0.0112 N×s2 / m9×yr, and the degree of increase in their resistivities over 4-9 years of existence reaches 7-8 times. The rate of aging of the mine workings is much lower than that of the local workings, averaging 0.0014 N×s2/m9×year for the inclined workings on average over the entire period of their existence, and 0.0009 N×s2/m9×year for horizontal ones. The degree of increase in the resistivity of capital workings for 12-25 years of their existence reaches 3 times. The workings were ranked by relative aerological risk indicator Rac by aerodynamic aging factor. The calculations showed that the average value of the relative aerological risk indicator for the aerodynamic aging factor of the Rac mine workings for the local haul drifts was 0.541; for precinct ventilation drifts - 0.842; for capital inclined workings - 0.172; for capital horizontal workings - 0.101. When assessing the risk of gassing of workings, it is necessary to take into account data on the aerodynamic aging of mine workings.

Change in the Rock Pressure when Mining a Coal Seam with a Longwall Face

2021 ◽  
pp. 65-69
Author(s):  
M.V. Shinkevich ◽  
◽  
R.I. Rodin ◽  
Keyword(s):  
Coal Mining ◽  
Rock Pressure ◽  
Average Rate ◽  
Rock Density ◽  
The Face ◽  
Pressure Indicators ◽  
Special Approach ◽  
The One ◽  
A Site ◽  
Enclosing Rocks

Development of the geomechanical processes is of great importance for human activity in the underground conditions. Coal mining is accompanied by displacement of the enclosing rocks, which requires a special approach to study of the geomechanical processes. In particular, this is due to an increase in the productivity of the excavation sections. Increase in the volume of the second working, the length of the longwalls and the size of the extraction pillars will transform all the geomechanical processes occurring in the face. Modern coal mining technologies are associated with certain specific features of the displacement of enclosing rocks, which necessitate the development of new approaches to the study of the geomechanical processes. The intensification of work inevitably leads to a change in the geomechanical environment in the vicinity of the face. The article discusses the methods and means of studying the process of rocks displacement as a result of construction of the mine workings. For example, a site is selected at the mine named after S.M. Kirov, long-face No. 24-62. Depth to the developed seam is from 476 to 520 m from the installation chamber. Average thickness of the seam is 2.5 m, length of the face is 300 m, length of the pillar is 2500 m. The average rate of advance is 10 m / day. Based on the monitoring of the rock pressure indicators on the mechanized support section, the wave-like nature of the rock pressure distribution in a long-face during mining of the extraction pillar was determined. The surface of the pressure domes was rebuilt using the Surfer software product, which allowed to track the processes in the face part of the longwall. Data on the pressure in the roof supports were used. In the calculations, the average rock density was assumed to be 2.5 m3/t. Since the surface of the pressure vaults makes it possible to judge the processes in the bottomhole of the mined seam, the height of the random collapse zone is determined from the pressure readings in the support struts. It is the one which presses on the powered support. Repetitive areas of the increased rock pressure were noted approximately every 200–250 m. Profiles of the surface of pressure arches along the length and in the long-face building cross are given. Considering the processes of structuring the rock mass, an algorithm for finding the height of the pressure arch was developed, which ensures a satisfactory convergence with the actual data.

scholarly journals Modification of the roof bolt support technology in the conditions of increasing coal mining intensity

2019 ◽  
Vol 109 ◽  
pp. 00042 ◽  
Author(s):  
Oleksandr Krukovskyi ◽  
Yurii Bulich ◽  
Yuliia Zemlianaia
Keyword(s):  
Coal Mining ◽  
Mine Working ◽  
Stable State ◽  
Roof Bolt ◽  
Suggested Approach ◽  
Roof Bolting ◽  
Working Face ◽  
The Face ◽  
Mine Workings ◽  
Host Rocks

The modification of the technology roof bolt supporting of mine workings in the conditions of increasing the coal mining intensity has been made. The technological schemes have been developed for the phased construction of roof bolting and frame support. This schemes make it possible to temporarily postpone the setting of frames in the mine working face, reduce the time and labour intensity for covering with a grid of the mine working arch and setting the bolts, as well as to increase the safety. The analysis of changes in the stress state of the border massif during the phased construction of roof bolting and frame support has been made. It is shown that the technology of phased construction of roof bolting and frame support ensures the maintaining a stable state of host rocks. In addition, the time between the extraction of the coal-rock mass and the setting of the primary support, as well as the distance between the face and the first row of roof bolts has been reduced to a minimum. The suggested approach makes possible to ensure the rate of preparatory mine workings development that are necessary for the intensification coal mining.

scholarly journals Mathematical modeling of tight roof periodical falling

2018 ◽  
Vol 60 ◽  
pp. 00020 ◽  
Author(s):  
Vira Prykhodko ◽  
Nataliia Ulanova ◽  
Oleksandr Haidai ◽  
Dina Klymenko
Keyword(s):  
Mathematical Modeling ◽  
Rock Mass ◽  
Boundary Element Method ◽  
Coal Seam ◽  
Mine Working ◽  
Strain State ◽  
Stress And Strain ◽  
Mine Workings ◽  
Roof Falling ◽  
Enclosing Rocks

The paper proposes a method to determine of a coal seam roof falling step basing upon the analysis of stress and strain state of the rock mass area with mine workings formed as a result of coal preparatory and extraction operations. A boundary element method has been applied to define stress and strain state (SSS). Fissuring of enclosing rocks was modeled by means of transversal-isotropic medium. Dependence of destructed rocks zone height within the roof of a seam being mined upon the weakening of the rock mass due to its fissuring and mine working geometry has been determined. Effect of fissility on the periodical roof falling step has been studied. Changes in support loads in the process of stope advance have been determined. A scheme of partial backfilling of the worked out area has been proposed to maintain the support in its working order.

scholarly journals Self-regulating roof-bolting with the rock pressure energy use

2018 ◽  
Vol 60 ◽  
pp. 00009 ◽  
Author(s):  
Oleh Khomenko ◽  
Maksym Kononenko ◽  
Ihor Kovalenko ◽  
Denys Astafiev
Keyword(s):  
Rock Pressure ◽  
Energy Use ◽  
Entropy Method ◽  
Underground Mine ◽  
Zonal Disintegration ◽  
Resource Saving ◽  
Roof Bolting ◽  
Underground Mine Workings ◽  
Mine Workings ◽  
Zonal Disintegration Phenomenon

The perspective of discovery of zonal disintegration phenomenon of rocks around underground mine workings is analyzed. The methodological stages for research of this phenomenon are shown. The physics of zonal disintegration of rocks around underground mine workings is disclosed. There are described the possibilities of advanced entropy method and developed energy method that allow to investigate a phenomenon of zonal capsulation of underground mine workings. The sequence of research of this phenomenon parameters is presented. The order of choice of stable shape and resource-saving support in underground mine workings is substantiated, for the deep horizons of the Kryvorizkyi Iron-Ore Basin mines. The method of parameters calculation of self-regulating roof-bolting in underground mine workings is substantiated, which allows to use the rock pressure energy. The design of a self-regulating roof-bolting is developed, which allows applying metal, polymer and rope bolts. The economic efficiency of rock pressure energy usage is substantiated in case of support setting at great depths in underground mine workings.

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

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.

scholarly journals Forecast for the formation of zones of high rock pressure in the conditions of mining ore deposits in a combined way

2019 ◽  
Vol 129 ◽  
pp. 01021
Author(s):  
Marina Potapchuk ◽  
Boris Saksin ◽  
Aleksandr Sidlyar ◽  
Andrey Tereshkin ◽  
Maksim Rasskazov
Keyword(s):  
Rock Pressure ◽  
Ore Deposits ◽  
Open Pit ◽  
Eastern Region ◽  
Structural Elements ◽  
Ore Bodies ◽  
Mine Workings ◽  
The Stability ◽  
Far Eastern ◽  
Underground Method

The prospect of mining the majority of deposits in the Far Eastern region is associated with the need to switch from the open-pit to the underground method of developing deep-lying ore bodies. Ensuring the safest conditions for the combined development of the field is possible only after comprehensive studies have been carried out that make it possible to establish the peculiarities of the formation of the stress state in the rock mass taking into account the influence of various natural and technogenic factors. An assessment of the stability of structural elements of the proposed development systems at the deposits will allow identifying potentially impact hazardous areas and developing measures to maintain and protect mine workings, which will reduce the risk of dynamic manifestations of rock pressure.

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