Evolution law and engineering application of surrounding rock force chain in shallow coal seam working face

被引：0
|
作者：
Xie G. [1 ]
Fan H. [2 ]
Wang L. [1 ]
机构：
[1] State Key Laboratory of Mining-induced Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan
[2] State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou
来源：
Meitan Xuebao/Journal of the China Coal Society | 2019年 / 44卷 / 10期
关键词：
Force chain evolution; Shallow coal seam; Strong dynamic load; Support stress;
D O I：
10.13225/j.cnki.jccs.2019.0706
中图分类号：
学科分类号：
摘要：
In the process of shallow seam mining, the rock pressure in mine appears intense, and the collapse accidents of support occur from time to time, which seriously restricts the safe and efficient mining of coal resources. In view of the sudden and violent rock pressure in the process of coal seam mining, the mechanical characteristics of surrounding rock and the stress characteristics of support structure are systematically studied. Firstly, the evolution characteristics of the surrounding rock force chain in working face are simulated by the particle element calculation software. Then, the mechanical models before and after the instability of the overburden strong force chain arch, and the support force model are established respectively. The track equation of the strong force chain arch is deduced, and the formulas for calculating the support load before and after the instability of the strong chain arch are obtained. On this basis, the support load of working face is studied, combined with field measurement. The results show that before the excavation of coal seam, the mechanical structure of coal and rock mass is composed of force chain network, and the bearing capacity of surrounding rock mainly comes from the strong force chain, while the widely distributed weak force chain only plays an auxiliary bearing role on surrounding rock. After the excavation of coal seam, the strong force chain forms a force chain arch, which is the main load bearing capacity of coal and rock mass above the stope. The support of working face only bears the weight of coal and rock under the strong force chain arch. With the advance of working face, the strong force chain arch is constantly adjusted, it has a dynamic evolution process of "formation-expansion-stability-breakage". The strong force chain arch development will lose stability and break, when its load exceeds its own strength limit, resulting in severe rock pressure phenomenon. The support load of the working face increases greatly. The unstable fracture of the strong force chain arch is the essential reason for the strong dynamic load in the working face. The research results reasonably explain the sudden severe rock pressure in shallow seam working face, which has theoretical significance and engineering application value for the safe and efficient mining of coal seam. © 2019, Editorial Office of Journal of China Coal Society. All right reserved.
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页码：2945 / 2952
页数：7
相关论文
共 20 条
  • [1] Huang Q., Qian M., Shi P., Structural analysis of main roof stability during periodic weighting in longwall face, Journal of China Coal Society, 24, 6, pp. 581-585, (1999)
  • [2] Xu J., Zhu W., Ju J., Supports crushing types in the longwall mining of shallow seams, Journal of China Coal Society, 39, 8, pp. 1625-1634, (2014)
  • [3] Li F., Study on ground pressure characteristic of shallow coal seam longwall mining and its safe exploitation demarcation, (2007)
  • [4] Yang Z., Instability behavior for roof strata in shallow seam longwall mining, Journal of China Coal Society, 33, 12, pp. 1341-1345, (2008)
  • [5] Ren Y., Ning Y., Qi Q., Physical analogous simulation on the characteristics of overburden breakage at shallow longwall coalface, Journal of China Coal Society, 38, 1, pp. 61-65, (2013)
  • [6] Hou Z., Analysis of combinatorial key strata stability in shallow coal seam with thick loose bed, Journal of China Coal Society, 25, 2, pp. 127-131, (2000)
  • [7] Li J., Liu C., Zhao J., Multiple factor sensitivity analysis of strata pressure behaviour in shallow coal seam mining, Journal of Mining & Safety Engineering, 33, 5, pp. 853-859, (2016)
  • [8] Du F., Yuan R., Zheng J., Et al., Mechanism of abnormal strata pressure of mining under coal pillar inclose distance shallow coal seams, Journal of China Coal Society, 42, pp. 24-29, (2017)
  • [9] Wang B., Liang B., Sun K., Et al., Research on overlying strata response and control during typical shallow coal seam longwall mining, Rock and Soil Mechanics, 38, 9, pp. 2693-2700, (2017)
  • [10] Liang B., Jia L., Sun W., Similarity simulation experimental study on movement behavior of overlying strata in full-mechanized caving mining of shallow coal seam, Journal of Safety Science and Technology, 10, 9, pp. 30-35, (2014)
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