Stress analysis of longwall top-coal caving face adjacent to the gob

Wang, J. C.; Wang, Z. H.; Yang, Shuo

doi:10.1080/17480930.2019.1639007

Cited by 12 publications

(6 citation statements)

References 21 publications

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“…e properties for gob materials are determined by comparing the predicted data with the empirical equation proposed by Salamon [18], which are listed in Table 3. Note that evolution of the cap pressure composed of the doubleyield model is controlled with the model proposed by Wang et al [31]:…”

Section: Model Configurationmentioning

confidence: 99%

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Ground Response and Mining-Induced Stress in Longwall Panel of a Kilometer-Deep Coal Mine

Wang

Yang

et al. 2021

Shock and Vibration

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In order to improve ground control of the longwall mining, ground response and mining-induced stress in the longwall panel of a kilometer-deep coal mine are investigated in this study. Field measurements on abutment stress, roof displacement, and fracture development indicate that the region influenced by the longwall mining reaches 150 m ahead of the longwall face. Failure scope of the coal seam, where mining-induced fractures are well developed, ranges from 10 to 13 m inward the face line. Vertical stress concentration coefficient reaches 2.2. Based on the field measurements, a numerical model is moreover developed and utilized to examine the response of the principal stress to the longwall mining. The concentration coefficient, peak point location, and influence scope of the principal stress gradually become stable with an increase in face advancement. Regarding the major principal stress, the concentration coefficient and influence scope are 2.4 and 152 m, respectively, and the peak point locates 13 m inward the face line, which are consistent with the field measurements. With respect to the minor principal stress, the referred coefficient and scope are 1.5 and 172 m, respectively, and its peak point location is 21 m ahead of the face line. The major principal stress in the coal seam rotates from vertical to horizontal direction in the vertical plane parallel with face advance direction. The maximum rotation angle reaches 20°. The minor principal stress first rotates into the referred vertical plane and then it rotates from horizontal to vertical direction at the same speed with the major principal stress in the same plane. Rotation angle of the principal stress in roof strata is greatly enlarged, the rotation trace of which is influenced by the longwall mining and vertical distance above the seam. Based on the relation between rotation trace of the principal stress and face advance direction, the influence of stress rotation on the stability of roof structure is discussed.

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Section: Model Configurationmentioning

confidence: 99%

“…Such stress rotation also occurred in the top coal during longwall top-coal caving. e rotation trace depended heavily on the panel layout, which influenced top-coal cavability to a large extent [29][30][31]. In deep coal mines, stress-relief measures were commonly carried out to control problems related to mining-induced stress.…”

Section: Introductionmentioning

confidence: 99%

Ground Response and Mining-Induced Stress in Longwall Panel of a Kilometer-Deep Coal Mine

Wang

Yang

et al. 2021

Shock and Vibration

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“…Currently, with the aid of numerical simulation, monitoring, theoretical analysis, and similar simulation methods, the structural damage and fracture evolution of the overburden with shallow coal seam and large mining height in the western mining area have been studied, which monitor the ground subsidence of the working face and the characteristics of the roof pressure and analyze the dynamic changes of the overburden [4][5][6][7][8]. When mining shallow and thin bedrock coal seams, the relationship between roof geological structure, mining space parameters, and roof stability was obtained [9][10][11]. Under the strong mining disturbance caused by high-intensity rapid mining to the migration of overburden, the law of failure and migration of key stratum under the condition of shallow coal seam thin bedrock and large mining height was established.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Hydraulic Coupling on Mechanical Deformation Characteristics of Shallow Coal Seam in Western Mining Area

et al. 2022

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During coal mining, the mechanical and deformation behavior of the overburden is affected by water and stress. Therefore, it is of great significance to study the mechanical behavior of the surrounding rock under the action of hydraulic coupling. For high-intensity mining with shallow coal seam and large mining and strong strata behavior in stope, the hydraulic support is often damaged. Based on basic experiments and physical similarity simulations, overburden fracture in shallow coal seam in western mining area under hydraulic coupling was studied. The results show that under the loading rate range of 0.5~5 mm/min, the compressive strength of sandstone increases with the loading rate. The faster the loading rate, the shorter the duration of the rock sample being loaded and damaged, and the fewer the acoustic emission events. The first weighting step of the main roof of the working face is 54 m, the periodic weighting step is 12.75~28 m, and the average periodic weighting step is 22 m. There are only caving zone and fractured zone in the overburden of working face; the height of caving zone and fractured zone is 60 m and 168 m, respectively. The strength of the saturated sample is significantly reduced. During the excavation of the working face, the temperature difference between the fracture and the overburden value is ≥1°C, which can be used as a threshold for judging the development range of overburden fracture in similar simulation experiments.

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“…This remained portion of coal is quite advantageous for improving the stability of the longwall mine, especially when the surrounding rock is relatively weaker than the remained coal. There are abundant research works that study on longwall mining development in thick coal seam [18][19][20][21]. Some also integrate weak geological conditions [1,22].…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Longwall Gate-Entry Stability under Weak Geological Condition: A Case Study of an Indonesian Coal Mine

et al. 2020

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The present research primarily focuses on the investigation of gate-entry stability of longwall trial panel under weak geological condition in Indonesia coal mine by means of numerical analysis. This work aims at identifying appropriate roof support at 100 m and 150 m of depth during gate development. Due to depth depending competency of dominant rock, the stability of gate-entry at 100 m of depth can be optimized by leaving at least 1 m of remaining coal thickness (RCT) above and below the gate-entry. The appropriate support for the trial panel gate-entry is steel arch SS540 with 1 m and 0.5 m spacing for 100 m and 150 m of depth, respectively. The influence of panel excavation on gate-entry is also discussed. Regarding the aforementioned influence, the utilization of additional gate mobile support is recommended at least 10 m from the longwall face.

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Stress analysis of longwall top-coal caving face adjacent to the gob

Cited by 12 publications

References 21 publications

Ground Response and Mining-Induced Stress in Longwall Panel of a Kilometer-Deep Coal Mine

Ground Response and Mining-Induced Stress in Longwall Panel of a Kilometer-Deep Coal Mine

The Effect of Hydraulic Coupling on Mechanical Deformation Characteristics of Shallow Coal Seam in Western Mining Area

Numerical Analysis of Longwall Gate-Entry Stability under Weak Geological Condition: A Case Study of an Indonesian Coal Mine

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