Wyniki wyszukiwania - BazTech

1

Slope reinforcement design based on GeoStudio and FLAC3D

Yu Rongxia, Huang Zhian, Yang Zhiquan

Mining Science

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2022

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Vol. 29

141--163

EN

Slope stability of open pit mines has been a hot issue of economic and safety concern. In order to reduce the accidental casualties caused by slope instability, targeted reinforcement solutions should be proposed for them. In this paper, GeoStudio and FLAC3D software were used to model the slope an open pit mine. The safety factors of the slope under natural, rainfall and seismic conditions are analyzed in turn. Additionally, the safety factors derived from different algorithms are compared to mutually verify the reliability of the slope stability analysis. Two sets of reinforcement design solutions – anchor rod and anti-slip pile – are proposed. Then, the two solutions are optimized so that the safety factors of the slope under three conditions reach 1.3, 1.2 and 1.1, respectively, and the optimal solution is selected from the two solutions by combining the economic benefits. The results show that the optimized anchor and anti-slide pile reinforcement solutions result in the safety factors of the slope under different conditions, reaching 1.441, 1.258, and 1.324 and 1.4, 1.238, and 1.23, respectively. The anti-slide pile reinforcement solution is more economical than the anchor reinforcement solution, so it is recommended that the anti-slide pile reinforcement solution should be chosen as the final solution.

2

Numerical simulation study on fire hazard of a coal mine transport roadway

Peng Shijie, Huang Zhian, Dong Ding Wen

Mining Science

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2022

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Vol. 29

33--52

EN

Due to the special structures and geographical environments of the main transport roadway of underground coal mines, it is difficult to deal with accidents and rescues in cases of fire and it is easy to cause casualties and structural damage of the roadway. In this study, a roadway fire model was established using FDS software on the basis of theoretical analysis. The smoke diffusion, temperature distribution, and CO concentration distribution in a fire period were simulated under four working conditions. The results showed that the time required for the smoke layer to descend to human breathing height was positively correlated with the distance between the position and the fire source. Under the most unfavorable conditions, the smoke reached human breathing height at 15.11 s and 100 m away from the fire source. After the fire broke out, the ambient temperature in the roadway rose rapidly, and the highest temperature in the area adjacent to the fire source reached 340 ℃. The farther away from the fire source, the lower the temperature, but it was still higher than the human body's optimum temperature (25 ℃) until 200 m away. The results of this study can provide a basis for the preparation of roadway fire emergency plans.

3

Theoretical analysis of support stability in large dip angle coal seam mined with fully-mechanized top coal caving

Ji Yucheng, Zhang Yinghua, Huang Zhian, Shao Zhenlu, Gao Yukun

Mining Science

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2020

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Vol. 27

73--87

EN

Support stability is critical to ensure fully-mechanized top coal caving of large dip angle coal seam. To obtain the relations between each factor and hydraulic support stability, the mechanic model of large dip angle coal seam along face dip and strike was built to analyze support stability, including antitoppling, anti-slip, and anti-rotation of supports. The result indicates: Along the face dip, the suport stability was negatively correlated with dip angle; Higher top caving means lower anti-rotation at suport tail; With initial support force and working resistance of supports enhanced, the anti-slip, and antirotation stability of supports can be risen significantly. Along the strike, the critical toppling angle was proportional to dip angle, mining height, support weight, support width and support force; The critica slip angle was positive correlation with support force, friction coefficient of roof and supports. According to the results of both mechanical analysis and engineering projects, support stability in large dip angle can be risen efficiently and supports slipping, toppling and rotation can be avoided by selecting proper technical methods and equipment, like enhancing initial support force appropriately.