Inclined seam
WebApr 11, 2024 · The accurate identification of gas migration channels and enrichment regions is essential for the utilization of gas resources and safe coal mine production, which are closely related to the evolution of mining-induced fractures. Therefore, we conducted a similarity simulation study of inclined coal seam group multiple mining, adopting the 1930 … WebOct 16, 2024 · The residual deformation of a goaf is studied to improve the foundation stability assessment for metro lines passing through the subsidence area of steeply inclined extra-thick coal seams. The variable mining influence propagation angle is introduced to describe the special form of the rock movement. Based on the modified parameters in the …
Inclined seam
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WebMar 24, 2024 · Extremely thick inclined coal seam generally exceeds 30 m (locally even over 200 m), and the dip angle of the strata exceeds 10°. In this kind of coal seam in the process of surface mining, the pit depth will increase year by year with the advancement of the working slope, and the production stripping ratio increases (Figure 1) [ 28 ]. WebApr 9, 2024 · The inclined seam causes stress to concentrate on the right side of the model, resulting in a “gentle slope” shape with greater damage in the upper right corner than on the left side. By extracting the damaged cells, a clear three-dimensional shape of the underground coal mine reservoir can be seen . The morphology indicates that the damage ...
Based on numerical simulations of top coal drawing for different seam dip angles under the same boundary of the top coal, the coordinates of the point A can be determined by analyzing the initial coordinates of the first drawn rock particle. The equation for the drawing body in the normal drawing stage can … See more Using the values of the basic numerical simulation parameters from Zhang et al. (2024a), namely, hm = 9 m, LOL = 1.7 m, LOW = 1.5 m, β = 60°, and θG = 50°, the … See more The variations of θA and ρmax with seam dip angle in the initial and normal drawing stages are shown in Fig. 15. In the normal drawing stage, in contrast to the … See more WebJan 1, 2002 · In summary, the state-of-art of subsidence prediction is that for gently inclined seams theoretically sound models and prediction methods are available, while for seams with a larger dip angle there are only empirical formulas instead of systematic models. Thus, study of mining subsidence above steep seams and establishment of an adaptable ...
WebSep 16, 2024 · When the coal seam inclination angle was 30°, the pressure was generated once every 8~15 m at the working face, with an average of 10.5 m (Table 5 ), which was 0.23~0.43 times greater than the initial pressure. Table 5 30° inclination model face cycle pressure step Full size table WebMar 26, 2024 · The roof rock structure of large dip coal seam stope is regarded as the movement of beam structure block under the stress condition of inclined fixed constraint boundary self-weight and uniform load on the boundary above the key layer, and it is assumed that the rock block meets the assumptions of material mechanics and elasticity.
WebFeb 1, 2016 · The thickness of coal seam No. 6–2 is 19.8 m. The working face is at depth between 603–657 m with an inclined length of 93 m and a strike length of 1036 m. The …
WebJul 12, 2024 · The steeply inclined coal seam is widely distributed in China, with its large dip angle and complex geological structure, which makes the mining of steeply inclined coal seam a difficult problem in mining technology for a long time, which has plagued the development of China’s coal industry. With the depletion of coal resources in the east ... high school counselor annual calendar exampleWebMar 14, 2024 · China’s proven reserves of steeply inclined coal seams account for about 20% of its total coal resources, but its annual mining volume only accounts for 4% of the total coal mining volume, showing huge mining potential of steeply inclined coal seams in the future [].Notably, in provinces such as Yunnan, Guizhou, and Sichuan in Southwest … high school coop programWebApr 11, 2024 · The results showed that under inclined coal seam group multiple mining, the frequency, angle and width of mining-induced fractures exhibited significant asymmetric … high school counselor blsWeb2 days ago · The potential of sudden water accidents induced by damage to the bottom slab that forms a water channel due to the action of karst water calls for research on the damage law of coal seam floors under the coupling effect of mining and karst water. In this study, the coupling situation of karst water and floor rock was analyzed based on the theory of rock … how many cedar blocks per closetWebMar 1, 2024 · When a coal seam is inclined, the horizontal stress reduces the stability of the pillar by increasing the potential of sliding along the bedding planes. A simplified mathematical expression of stress distribution on an inclined coal pillar is … high school counseling newsletterWebAug 8, 2024 · Sloped ground and inclined seams were produced by the rotary motion of the trap-door model around its center of rotation. The downward movement of the trap door … high school cornell notesWebMay 19, 2024 · China has large reserves of steeply inclined coal seams, accounting for 15% to 20% of the total coal reserves, and more than 50% of the mines in western China are mining steeply inclined coal seams . The mining of steeply inclined coal seams often results in surface collapse pits and stepped depressions [ 2 ], which pose a great threat to ... high school cops