Stability of goaf-side entry driving in 800-m-deep island longwall coal face in underground coal mine

Qian, Deyu; Zhang, Nong; Shimada, Hideki; Wang, Cheng; Sasaoka, Takashi; Zhang, Nianchao

doi:10.1007/s12517-015-2119-6

Cited by 29 publications

(20 citation statements)

References 13 publications

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“…The formula for calculating the stress limit equilibrium zone width established by Hou and Ma [29] using the loose medium limit equilibrium theory has been widely applied in various scientific research and engineering projects [35][36][37]. The formula is expressed as…”

Section: A Discussion About the Modelmentioning

confidence: 99%

Prediction Model of Failure Zone in Roadway Sidewall considering the Lithologic Effect of Rock Formation

Zhao

Chen

et al. 2018

Mathematical Problems in Engineering

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Coal seam damage area and its stress distribution law in roadway with medium thickness or extrathick coal seam are important issues for understanding the instability mechanism of roadway surrounding rock in weakly cemented soft rock strata in western China. Firstly, a variable parameter microelement analysis model is established based on the assumption of a plane stress integrating with the coal seam-rock’s interface and the rock formation on both sides; moreover, a formula is established by the strain compatibility relationship to express the state of stress in rock bodies on both sides of the interface. Then, a method for calculating the stress limit equilibrium zone width of the coal side and regional stress distribution is presented, which considers the coupling effect of the coal side-rock formation and is based on the loose medium limit equilibrium theory. Finally, the validity of the model is verified through a comparison with previous research and by being applied to an engineering example. The results show the following: (1) the interface adhesion effect results in an abrupt change of the stress state of both the rock formation and coal seam and is related to their deformation parameters; i.e., there is a coupling effect; (2) the limit equilibrium zone width is not only related to the buried depth of the roadway, excavated coal seam thickness, coal seam strength parameters, stress concentration factor, lateral pressure coefficient, and supporting strength of the side of the roadway, but it also has an effect on the aforementioned coupling effect; (3) due to the roof-coal seam-floor comprehensive structural effect, the model presented in this paper is applicable to both the coal seam failure and the failure along the coal seam-rock’s interface.

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Section: A Discussion About the Modelmentioning

confidence: 99%

Prediction Model of Failure Zone in Roadway Sidewall considering the Lithologic Effect of Rock Formation

Zhao

Chen

et al. 2018

Mathematical Problems in Engineering

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“…Meanwhile, the residual bending moment of the beam fracture, M A , is much less than the bending moment occurring in the main roof, M O . By comparing the theoretical models for the fracture of the main roof at the gob side and at the solid coal side and Equations (10) and (17), obviously, the temporary support strength in the roadway when the fracture site of the main roof is at the solid coal side is greater than that required at the gob side; namely P 1 > P 3 . The fracture occurrs above the roadway; one end of block B is on the roadway, and there is no supporting force of the solid coal.…”

Section: Asmentioning

confidence: 99%

“…Following the development path of environment-friendly, safe, high-efficient, non-pillar mining technology, it has been widely used in coal mining. Gob-side entry retaining is a common practice of non-pillar mining in mine shafts, which significantly improves the coal recovery rate, reduces the roadway excavation, allows for the Y-type ventilation on the mining face, and addresses the gas accumulation at the corners of the working surface [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Stability Analysis of the Entry in a New Mining Approach Influenced by Roof Fracture Position

Yang

Wang

et al. 2019

Sustainability

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Non-coal pillar mining with roadway formed automatically (RFANM) is a new mining approach, which demonstrates revolutionary significance because it does not require making roadway before mining and coal pillar retaining. In order to explore the stability of the surrounding rock structure in RFANM, the deformation of the surrounding rock was theoretically analyzed and simulated based on three different fracture positions of the main roof. It was concluded that reasonable control of temporary support strength in roadway is of great importance to control the deformation of the entry. The deformation process of surrounding rock under different fracture positions in RFANM was simulated by using the Universal Discrete Element Code (UDEC). The results of the numerical simulation showed that the main roof was fractured at the solid coal side or gob side; the deformation of the roadway was small. The fracture condition of the main roof at the gob side required a higher effect of roof slitting or temporary support from the roadway. Through drilling and peeping at the retained roadway, it was judged that the main roof was broken inside the coal wall. Field monitoring results revealed that the deformation of the roadway can be effectively controlled.

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“…The high dynamic pressure often results in excessive entry deformation and convergence. The cutting cantilever beam theory [32] was proposed to determine the optimal gob-side entry location in GER and the reasonable rib pillar width in GED [9,12,13,16,17,21,23,31,33,34].…”

Section: Previous Studies On Gob-side Entriesmentioning

confidence: 99%

A New Gob-Side Entry Layout Method for Two-Entry Longwall Systems

et al. 2018

Energies

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Abstract:The gob-side entry layout is popular at two-entry longwall mine sites in China for the benefit of improving the coal recovery rate. Currently, two methods have been widely used to develop gob-side entries, including gob-side entry retaining and gob-side entry driving. Gob-side entry retaining maximizes the recovery rate by pillarless mining but increases the difficulty in gob-side entry support. Also, this method has limited applications in hard roof conditions. The gob-side entry driving mine site uses the rib pillar to separate the gob entry and the gob area of the previous panel, which leads to additional coal losses. The waste is more intolerable in large-cutting-height panels and longwall top coal caving panels as the Chinese government limits the minimum recovery rate of longwall panels using these mining methods. In this paper, a new gob-side entry layout method, termed gob-side pre-backfill driving, is established to overcome the shortcomings of the existing methods. The new method eliminates rib pillar losses and enhances gob-side entry stability. The feasibility of gob-side pre-backfill driving is studied by numerical modelling and a field trial at Changcun Mine in China. The results indicate that gob-side pre-backfill driving is an alternative for gob-side entry development. This method is practical and also has the potential to bring significant economic benefits to the mining industry.

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Stability of goaf-side entry driving in 800-m-deep island longwall coal face in underground coal mine

Cited by 29 publications

References 13 publications

Prediction Model of Failure Zone in Roadway Sidewall considering the Lithologic Effect of Rock Formation

Prediction Model of Failure Zone in Roadway Sidewall considering the Lithologic Effect of Rock Formation

Stability Analysis of the Entry in a New Mining Approach Influenced by Roof Fracture Position

A New Gob-Side Entry Layout Method for Two-Entry Longwall Systems

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