Fang Shuhao, Zhu Hongqing, Huo Yujia, Zhang Yilong, Wang Haoran, Li Feng, Wang Xiaokuan
School of Emergency Management and Safety Engineering, China University of Mining and Technology-Beijing, Beijing, China.
State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology-Beijing, Beijing, China.
PLoS One. 2021 Jan 28;16(1):e0246199. doi: 10.1371/journal.pone.0246199. eCollection 2021.
To design underside protective seam strip layout. Similarity model experiments, numerical simulations and theoretical calculations are used to quantitatively study the pressure relief protection effect of different strip widths, dip angles and coal pillar widths of a thin underside protective seam under deeply buried conditions. The optimal strip width range is obtained according to the change law of strain during the mining process of the underside protective seam in a similar model experiment. The change law of the expansion of the protected coal seam is obtained and the fitting surfaces among the dip angle and strip width of the coal seam with the protection distance and pressure relief angle along the strike and dip of the protected coal seam are established according to the numerical simulation results of underside protective seam mining. It is concluded that the best pressure relief effect can be achieved when the dip angle is 16.7° and the strip width is 70 m. According to the stability threshold of coal pillars considered in strip mining theory, the coal pillar width is calculated to be 50 m. Similarity model experiments and numerical simulations of protected coal seam mining verify the pressure relief effect of the designed protective seam strip width and pillar width. A calculation method of the protective seam strip width, position and pillar width required by the specific width of the protected seam is proposed.
进行底板保护条带布置设计。采用相似模型试验、数值模拟和理论计算等方法，定量研究深埋条件下薄煤层底板保护条带不同条带宽度、倾角和煤柱宽度的卸压保护效果。根据相似模型试验中底板保护煤层开采过程中应变的变化规律，得出最佳条带宽度范围。根据底板保护煤层开采的数值模拟结果，得出被保护煤层膨胀的变化规律，并建立了煤层倾角、条带宽度与沿被保护煤层走向和倾向的保护距离、卸压角之间的拟合曲面。得出当倾角为16.7°、条带宽度为70 m时，卸压效果最佳的结论。根据条带开采理论中考虑的煤柱稳定性阈值，计算得出煤柱宽度为50 m。被保护煤层开采的相似模型试验和数值模拟验证了所设计的保护条带宽度和煤柱宽度的卸压效果。提出了针对特定被保护煤层宽度所需的保护条带宽度、位置和煤柱宽度的计算方法。
