Stability of coal pillar in gob-side entry driving under unstable overlying strata and its coupling support control technique

Zhang, Yuan; Wan, Zhijun; Li, Fuchen; Zhou, Changbing; Zhang, Bo; Guo, Feng; Zhu, Chengtan

doi:10.1016/j.ijmst.2013.04.020

Cited by 45 publications

(19 citation statements)

References 3 publications

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“…Hence it requires higher working resistance, larger resistance-increasing velocity, and enough yield ability on related supports in retained entry (Qian et al 2010). The kernel to the success of GER is whether the entry-side supports can adapt to the movement law of roof and efficiently control the roof strata or not (Li 2000;Yang et al 2013;Zhang et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Position-optimization on retained entry and backfilling wall in gob-side entry retaining techniques

Feng

Zhang

2015

Int J Coal Sci Technol

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This study investigates the stability problem of gob-side entry retaining (GER) and backfilling wall which located under the key block B. Based on the combined research of elastic-plastic mechanics, structure mechanics and modern theory of mining-induced pressure, the caving characteristic and roof structure over the GER were analyzed, and the vertical force and the torque on retained entry roof were also derived as the position for the retained entry varies. On the basis of the specific geology in Huainan mining area, the results indicate that a relatively more stable position for retained entry neighbors the hinge point of block A and B, and it also located at a scope ranging from this point to the one-third length of block B in horizontal direction. As to appropriate position for backfilling wall, this study recommends partialroad-in backfilling method for GER. Field trial conducted at panel face 12418 of Xieqiao Mine demonstrates that the recommended width for original entry is 3.6 m and the preferred width proportion between original retained entry and original entry is 75 % or so whereas the avoidable one is 88 % or so. These findings provide qualitative references to the mines which share similar geology as what Huainan mining area characterized.

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Section: Introductionmentioning

confidence: 99%

Position-optimization on retained entry and backfilling wall in gob-side entry retaining techniques

Feng

Zhang

2015

Int J Coal Sci Technol

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“…V. M. Seryakov et al [18] conducted research on the mining abutment pressure of the longwall face of fully mechanized mining; they also explored the stress distribution change law of coal and surrounding rock in the roadway driving stage when the roadway is in stagger arrangement. Yuan Zhang [19] studied the distribution law of abutment pressure in deep stope, established a dynamic mechanical model of the roof structure, and finally proposed the optimum design method of coal pillar width of gob-side entry with prevention of large deformation of roof as the core. T. Mallhao et al [20] studied the evolution law of the vertical stress of coal pillars in four different stages by numerical simulation and established the coal pillar stability prediction model to solve the size design in room pillar mining.…”

Section: State Of the Artmentioning

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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“…The narrow coal pillar mining pattern is also known as gob-side entry driving [31][32][33]. The Generally, stabilities of the entry in a wide coal pillar mining pattern can be well guaranteed.…”

Section: Narrow Coal Pillar Miningmentioning

confidence: 99%

Analysis and Optimization of Entry Stability in Underground Longwall Mining

et al. 2017

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For sustainable utilization of limited coal resources, it is important to increase the coal recovery rate and reduce mine accidents, especially those occurring in the entry (gateroad). Entry stabilities are vital for ventilation, transportation and other essential services in underground coal mining. In the present study, a finite difference model was built to investigate stress evolutions around the entry, and true triaxial tests were carried out at the laboratory to explore entry wall stabilities under different mining conditions. The modeling and experimental results indicated that a wide coal pillar was favorable for entry stabilities, but oversize pillars caused a serious waste of coal resources. As the width of the entry wall decreased, the integrated vertical stress, induced by two adjacent mining panels, coupled with each other and experienced an increase on the entry wall, which inevitably weakened the stability of the entry. Therefore, mining with coal pillars always involves a tradeoff between economy and safety. To address this problem, an innovative non-pillar mining technique by optimizing the entry surrounding structures was proposed. Numerical simulation showed that the deformation of the entry roof decreased by approximately 66% after adopting the new approach, compared with that using the conventional mining method. Field monitoring indicated that the stress condition of the entry was significantly improved and the average roof pressure decreased by appropriately 60.33% after adopting the new technique. This work provides an economical and effective approach to achieve sustainable exploitation of underground coal resources.

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Stability of coal pillar in gob-side entry driving under unstable overlying strata and its coupling support control technique

Cited by 45 publications

References 3 publications

Position-optimization on retained entry and backfilling wall in gob-side entry retaining techniques

Position-optimization on retained entry and backfilling wall in gob-side entry retaining techniques

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

Analysis and Optimization of Entry Stability in Underground Longwall Mining

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