Design of coal pillar with roadway driving along goaf in fully mechanized top-coal caving face

Chang, Juan; Xie, Guangxiang; Yang, Keming

doi:10.1201/b11761-34

Cited by 6 publications

(8 citation statements)

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“…1,2 Sometimes, in order to meet the requirements of the installation and maintenance of underground electromechanical equipment and, washing and crushing of gangues, large-section chamber is formed by the local extension of the main roadway. Due to large production of the ultra-thick coal seam mining, the area of the large-section chamber shall be generally more than 100 m. [2][3][4] In general, coal seams are softer and easily broken than strata. On the other hand, with the large-section chamber, the damage range of surrounding rocks is large.…”

Section: Introductionmentioning

confidence: 99%

Failure characteristics and control technology for large‐section chamber in compound coal seams—A case study in Tashan Coal Mine

Tai

Xia

Kuang

2019

Energy Science & Engineering

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The coal production exploited from extra‐thick coal seams accounts for 45% of China's total coal production. With large coal output, the extra‐thick coal seams require that the chamber section be more than 100 m2. In case of parting (the noncoal rock, usually mudstone, sandwiched in the coal seam) in the extra‐thick coal seams, the integrity of the coal seams will be damaged and the large‐section chamber is extremely easy to occur rib spalling and roof leakage, which will increase the chamber's supporting difficulty. To solve such problems, this paper took the electromechanical chamber in Tashan Coal Mine as the engineering background and analyzed the deformation and failure characteristics of this chamber surrounding rocks by the numerical simulation method during the excavation process. The results indicated that the failure areas of surrounding rocks were mainly in partings, chamber ribs, and chamber dome with the failure depths of 15 m, 10 m, and 5 m, respectively. Based on the obtained deformation and failure characteristics, the supporting method of grouting integrated with high‐strength bolts and anchor cables was put forward. The grouting method was firstly used to improve the integrity of the chamber surrounding rocks, and the high‐strength bolts and anchor cables were used for supporting. Then, the supporting parameters of the bolts and anchor cables and the grouting parameters were optimized by the numerical simulation method. The optimized parameters were applied in the electromechanical chamber in Tashan Coal Mine, and the on‐site chamber ribs lateral displacement and roof separation amounts were only 0.018 m and 0.012 m, respectively, indicating that the surrounding rocks were controlled effectively.

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Section: Introductionmentioning

confidence: 99%

Failure characteristics and control technology for large‐section chamber in compound coal seams—A case study in Tashan Coal Mine

Tai

Xia

Kuang

2019

Energy Science & Engineering

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“…As shown in figure 1, the large-pillar method aims to arrange the roadway in the in situ stress area to avoid impacts of abutment pressure. This method is beneficial to maintain the roadway, but it will waste quite a large portion of coal resources [6]. In order to reduce the size of coal pillars and improve the coal recovery rate in coal mines, the small-pillar method has been developed.…”

Section: Introductionmentioning

confidence: 99%

“…It is designed to arrange the roadway in the stress reduction area of the surrounding rock. The width of small coal pillars is generally between 3 and 6 m [6]. By applying this method, the roadway will locate in the stress reduction area, which makes the maintenance of the roadway easier and increases the recovery rate of coal resources [7].…”

Section: Introductionmentioning

confidence: 99%

The sustainable development of coal mines by new cutting roof technology

Tai

Gao

et al. 2020

R. Soc. open sci.

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China consumes more than 3.6 billion tons of coal every year. In the meanwhile, coal accounts for over 60% of the energy consumption sector. Therefore, the sustainable development of coal mines is a problem that needed to be solved by the Chinese government. During the coal resources recovery process, the protective coal pillars between the adjacent working faces lead to a vast waste of coal resources. In order to mitigate the resource-wasting issue, a new technology of roof cutting with chain arm retaining roadway was put forward in this paper. First, the procedures of retaining roadway, roof-cutting parameters and the damage ranges of roadway surrounding rock induced by roof cutting with chain arm were analysed. Then, the working resistance of the temporary support equipment is given when using the new technology to retain the roadway. Next, the roof-cutting height, the temporary support equipment selection, working resistance of portal support and support parameters of the bolt and anchor cables were optimized based on the numerical calculation. The industrial experiment of retaining roadway by roof cutting with chain arm was carried out in a working face. The surrounding rock damage was lowered and controlled with the application of chain arm roof-cutting technology. Also, it was found that the variation range of the uniaxial compressive strength was only 5%, resulting in the roof damage range of 82 mm. The new technology has proved a potentially wide application in the coal mining industry with prosperous economic and safety improvement.

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“…Experts and scholars at home and abroad have proposed numerous methods and theories about the optimal design of the coal pillar width of gob-side entry. The main research aspects are as follows: determine the distribution of the side abutment pressure in the mining face through the field measurement of the mining abutment pressure to optimize the coal pillar width design [5][6]; calculate the coal pillar stress distribution under the mining abutment pressure by using elastic-plasticity theory to obtain the width calculation formula of the coal pillar in a stable state and achieve the optimization effect [7][8]; numerical simulation of the distribution characteristics of the mining abutment pressure and the stability of the surrounding rock of roadway under different coal pillar widths by using different computer software to optimize the coal pillar width design [9][10]; and summarize the distribution law of the mining abutment pressure according to the traditional field production experience and optimize the coal pillar width design based on existing experience [11][12]. Therefore, the existing optimum design of the coal pillar width of roadway driving along goaf is based on the distribution law of mining abutment pressure formed in the adjacent mining faces.…”

Section: Introductionmentioning

confidence: 99%

Distribution Law of Principal Stress Difference of Deep Surrounding Rock of Gob-side Entry and Optimum Design of Coal Pillar Width

Qiang

Wang

et al. 2019

Teh. vjesn.

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The optimum design of deep-coal pillar width at the gob-side entry is the key to control surrounding rocks. Existing studies on this issue are based on the distribution law of mining abutment pressure without considering the principal stress difference distribution, which is related to the shear failure of surrounding rock. This study aimed to optimize the design of deep-coal pillar width at gob-side entry based on the distribution law of the principal stress difference. With FLAC 3D numerical simulation, the distribution characteristics of principal stress difference in the side mining stress field of the deep mining face and the distribution laws of the principal stress difference of the surrounding rock at the gob-side entry under different coal pillar width were explored. According to the distribution characteristics of the principal stress difference, the coal and rock mass on the goaf side in the deep mining face could be divided into three zones, i.e., decreasing, increasing and stable zones. Results show that the principal stress differences of the deep surrounding rock on the roof, floor, and coal wall rib at the gob-side entry present a single-peak curve distribution under different coal pillar width. However, the principal stress difference of the surrounding rock on the coal pillar rib displays a single-peak curve when the coal pillar width is less than or equal to 8 m, but a double-peak curve appears when the coal pillar width is greater than 8 m. The peak value of the shallow surrounding rock is obviously smaller than that of the deep surrounding rock. The width of the coal pillar of the gob-side entry in 11030-tunnel was optimized according to the theoretical calculation. This work provides a novel idea and method for the arrangement of deep coal pillars of gob-side entry.

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Design of coal pillar with roadway driving along goaf in fully mechanized top-coal caving face

Cited by 6 publications

References 0 publications

Failure characteristics and control technology for large‐section chamber in compound coal seams—A case study in Tashan Coal Mine

Failure characteristics and control technology for large‐section chamber in compound coal seams—A case study in Tashan Coal Mine

The sustainable development of coal mines by new cutting roof technology

Distribution Law of Principal Stress Difference of Deep Surrounding Rock of Gob-side Entry and Optimum Design of Coal Pillar Width

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