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 Analytical and Mining Experimental Studies about the Character of Interaction on the Mechanized Supports of ZQY3600/12/28 at the Quang Hanh Mine in the Quang Ninh Coal Basin

2018 ◽  
Vol 41 ◽  
pp. 01036
Author(s):  
Thang Duc ◽  
Huynh Ngoc
Keyword(s):  
3D Model ◽  
Experimental Studies ◽  
Coal Seams ◽  
Coal Basin ◽  
Mechanized Support ◽  
Deformation State ◽  
Mining Works ◽  
Roof Rocks ◽  
Working Out ◽  
Quang Ninh

Complex studies using measuring stations for working out inclined coal seams of medium thick with the use of longwall, combining in a certain extracting area of mining works and instruments for measuring the bearing rock pressure and the displacement of the roof rocks adjacent to the longwall. The parameters of stress intensity distribution were placed during the working out of the extracting area. Installation of reaction dynamics mechanized support along the strike of extracting area. Suggestion 3D-model shows stress-deformation state of the rock massif in all of extracting area.

scholarly journals Mechanism of Rock Bursts Induced by the Synthetic Action of “Roof Bending and Rock Pillar Prying” in Subvertical Extra-Thick Coal Seams

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhenhua Wu ◽  
Peng-Zhi Pan ◽  
Jianqiang Chen ◽  
Xudong Liu ◽  
Shuting Miao ◽  
...  
Keyword(s):  
Rock Mass ◽  
Coal Seam ◽  
Rock Burst ◽  
Roof Rock ◽  
High Energy ◽  
Coal Seams ◽  
Rock Bursts ◽  
Rock Pillar ◽  
Mining Depth ◽  
Rock Burst Mechanism

When studying the rock burst mechanism in subvertical extra-thick coal seams in the Wudong coal mine in Xinjiang, China, most studies focus on rock pillars, while the effect of the roof on rock bursts is usually ignored. In this paper, a rock burst mechanism in subvertical extra-thick coal seams under the control of a “roof-rock pillar” is proposed. A theoretical analysis is first performed to explain the effect of roof-rock pillar combinations on rock bursts in coal seams. Numerical modeling and microseismic analysis are implemented to further study the mechanism of rock burst. The main conclusions are as follows: 1) During the mining of the B3+6 coal seam, an obvious microseismic concentration phenomenon is found in both the roof and rock pillar of B3+6. The rock bursts exhibited obvious directionality, and its main failure characteristics are floor heave and sidewall heave, but there will also be some failures such as shoulder socket subsidence in some parts. 2) The stress transfer caused by rock pillar prying is the main reason for the large difference in rock burst occurrence near the vertical and extra thick adjacent coal seams under the same mining depth. 3) Under the same cantilever length, the elastic deformation energy of the roof is much greater than that of the rock pillar, which makes it easier to produce high-energy microseismic events. With an increasing mining depth, the roof will become the dominant factor controlling the occurrence of rock bursts. 4) The high-energy event produced by the rock mass fracture near the coal rock interface easily induces rock bursts, while the high-energy event produced by the fracture at the far end of the rock mass is less likely to induce rock burst. 5) Roof deformation extrusion and rock pillar prying provide high static stress conditions for the occurrence of rock bursts in the B3+6 coal seam. The superposition of the dynamic disturbance caused by roof and rock pillar failure and the high static stress of the coal seam is the main cause of rock burst in the B3+6 coal seam.

scholarly journals DETERMINATION OF THE RATIONAL LENGTH OF THE BLOCK ALONG THE STRIKE FOR EXPANSION TO PROVIDE SAFETY AND EFFICIENCY IN THE WORKING OF THE MEDIUM THICK IN-CLINED COAL SEAMS WITH THE ROOM AND PILLAR SYSTEM IN THE QUANG NINH COAL BASIN

2018 ◽  
pp. 3-8
Author(s):  
Duc Thang Pham ◽  
Victor G. Vitcalov
Keyword(s):  
Coal Seams ◽  
Coal Basin ◽  
Foreign Experience ◽  
Geological Conditions ◽  
Rational Length ◽  
Working Out ◽  
Quang Ninh ◽  
Excavation Area

An analysis of the constraints that apply the technology and the complexities of the mining and geological conditions of the Quang Ninh coal basin. The possi-bility and expediency of using the foreign experience of working out of the me-dium thick inclined coal seams in the mines of Vietnam. The scheme of prepara-tion and working out of the excavation area is given in view of the technological features in difficult mining and geological conditions, using the room and pillar system and determination of the rational length of the block along the strike.

scholarly journals Justification of Spatially-Planned Solutions and Determination of the Dimension Block in the Working of the Medium Thick Inclined Coal Seams with the Room and Pillar System

2018 ◽  
Vol 41 ◽  
pp. 01024
Author(s):  
Thang Pham Duc ◽  
Anh Phan Tuan ◽  
Viktor Vitcalov ◽  
Phuc Le Quang
Keyword(s):  
Technological Parameters ◽  
Coal Seams ◽  
Coal Basin ◽  
Working Face ◽  
Geological Conditions ◽  
Rational Length ◽  
Working Out ◽  
Quang Ninh ◽  
Excavation Area

Technological parameters for working out of the medium thick inclined coal seams with a diagonal arrangement of a line of a working face. An analysis of the constraints that apply the technology and the complexities of the mining and geological conditions of the Quang Ninh coal basin. The possibility and expediency of using the foreign experience of working out of the medium thick inclined coal seams in the mines of Vietnam and justification of spatially-planned solutions for working. The scheme of preparation and working out of the excavation area is given in view of the technological features in difficult mining and geological conditions, using the room and pillar system and determination of the rational length of the block along the strike.

scholarly journals Hydrodynamic impact on coal mass before crossing the most outburst-prone coal seams

2019 ◽  
Vol 109 ◽  
pp. 00112
Author(s):  
Vasyl Vlasenko ◽  
Dmytro Zhytlonok
Keyword(s):  
Coal Seam ◽  
Experimental Studies ◽  
Coal Mass ◽  
State Enterprise ◽  
Coal Seams ◽  
Dynamic Activity ◽  
Hydrodynamic Impact ◽  
Gas Dynamic ◽  
Mine Workings ◽  
Hydrodynamic Effects

The results of experimental studies of hydrodynamic effects (HDI) in industrial conditions are given. The HDI is designed to reduce the gas-dynamic activity of the coal seam and the rocks surrounding it. HDI was applied to the coal seam before it crossed the mine workings. The conditions for the implementation of HDI in industrial conditions Separate Enterprise “Mine “Tsentralna” State Enterprise “Toretskvuhillia” are described. The results of HDI on coal seams m2 -“Tonkyi” and m3 -“Tovstyi” are given. The parameters of the HDI method for outburst-prone coal seam before its crossing by mine workings are corrected.

SUBSTANTIATION OF RATIONAL VARIANTS TECHNOLOGY IN THE WORKING OF THE MEDIUM THICK INCLINED COAL SEAMS WITH THE ROOM AND PILLAR SYSTEMS IN THE QUANG NINH COAL BASIN

Ugol ◽  
2018 ◽  
pp. 27-31
Author(s):  
Pham Duc Thang ◽  
◽  
V.G. Vitcalov ◽  
V.V. Agafonov ◽  
Nguyen Duyen Phong ◽  
...  
Keyword(s):  
Coal Seams ◽  
Coal Basin ◽  
Quang Ninh

Premine study of shallow coal seams using high‐resolution seismic reflection methods

Geophysics ◽  
1991 ◽  
Vol 56 (9) ◽  
pp. 1494-1503 ◽  
Author(s):  
Harvey Henson ◽  
John L. Sexton
Keyword(s):  
High Resolution ◽  
Seismic Reflection ◽  
Roof Rock ◽  
Drill Hole ◽  
Coal Seams ◽  
Borehole Data ◽  
Seismic Line ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Roof Rocks

Geological investigations in the Illinois Basin coalfields have shown that significant differences in safe and economical exploitation of coal depends directly on accurate mapping of the roof rock overlying the seam, as well as on geological structures in the coal measures. In roof rock transition zones above the Herrin (No. 6) coal where the nonmarine Energy shale changes to the Anna shale, a change often occurs from low to high sulfur coal and from low to high stability roof rocks. In many instances, use of borehole data alone is inadequate to locate these features in advance of mining. High‐resolution seismic reflection data collected near Harco, Illinois were used as part of premine planning to help predict roof instability, areas of low sulfur coal, and geologic disturbances. Several faults, channels, and facies changes affecting the Herrin (No. 6) and the Springfield (No. 5) coal seams at depths of 137 m and 167 m, respectively, were interpreted and modeled. One‐ and two‐dimensional synthetic seismograms calculated from geological data from drill holes along the seismic line were used to aid in the interpretion of the seismic reflection data. Results obtained from the high‐resolution reflection survey combined with drill hole information clearly show that use of borehole data alone is inadequate to locate geological features that might affect coal mine operations, even if the boreholes were spaced 25 m apart. Thus, high‐resolution reflection surveying should be employed whenever feasible for the safe and economical exploitation of coal deposits.

scholarly journals Analysis of the Geomechanical Phenomena that Led to the Appearance of Sinkholes at the Lupeni Mine, Romania, in the Conditions of Thick Coal Seams Mining with Longwall Top Coal Caving

2021 ◽  
Vol 13 (11) ◽  
pp. 6449
Author(s):  
Dacian-Paul Marian ◽  
Ilie Onica
Keyword(s):  
Laser Scanning ◽  
Ground Surface ◽  
Coal Seams ◽  
Coal Basin ◽  
Thick Coal Seam ◽  
Aerial Laser Scanning ◽  
Mining Depth ◽  
Mining Conditions ◽  
Elasto Plasticity ◽  
Longwall Top Coal Caving

Thick coal seam no. 3, block V, Lupeni mine was mined by longwall top coal caving (LTCC). After the coal mining, the ground surface underwent continuous subsidence, but since 2008, three sinkholes have appeared on the surface with important dimensions, atypical for the geo-mining conditions in this coal basin. This article is a synthesis of the study meant to decipher the geo-mechanical phenomenon that led to the emergence of these sinkholes and highlighting the main factors that contributed to the development of this phenomenon. For this purpose, measurements were made on the terrain deformations using photogrammetric methods and aerial laser scanning, when modeling with 3D finite elements, in elasto-plasticity and with the help of the Knothe–Budrik influence function. The factors that contributed to the occurrence of discontinuous subsidence phenomena are shallow mining depth, the LTCC mining method, and the presence of faults in the vicinity of the mining panels. Additionally, the geo-mechanical phenomena of subsidence terrace development and sinkholes in the mining subsidence troughs at the Lupeni mine were described.

Experimental studies of the extraction mine workings in a very weak rocks

2019 ◽  
pp. 218-228
Author(s):  
I.A. Kovalevska ◽  
◽  
O.S. Husiev ◽  
V.H. Snihur ◽  
O.K. Malova ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Weak Rocks ◽  
Mine Workings
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