Wu Yongping, Liu Mingyin, Xie Panshi, Wang Hongwei, Hu Bosheng
School of Energy and Mining Engineering, Xi'an University of Science and Technology, Xi'an 710054, China.
Ministry of Education, Key Laboratory of Western Mine Exploitation and Hazard Prevention, Xi'an University of Science and Technology, Xi'an 710054, China.
ACS Omega. 2022 May 4;7(19):16442-16453. doi: 10.1021/acsomega.2c00450. eCollection 2022 May 17.
To explore the variations of the loading, deformation, and loss and to determine the mechanical state, loss characteristics, and stability for the shaft coal pocket wall in coal mines under a dynamic-static load, this paper innovatively attempts to conduct a three-dimensional physical similarity test of a transparent material shaft coal pocket, as well as the experiments of loading and unloading coal in the shaft coal pocket using different bulk storage materials 80 times. Then, the deformation, pressure, the surrounding rock, and the flow pattern of the silo wall were discussed considering the existence of the warehouse wall support. The characteristics of shaft wall deformation and surrounding rock stress cracks during the unloading were analyzed with the help from multiple integrated test systems such as strain gauges, pressure sensors, borehole peeps, and other comprehensive test systems. The results indicated that different dispersion particles have a significant impact on the strain of the shaft wall. When using the coal particles as storage materials, the overpressure coefficient of the shaft wall is up to 1.95 times higher than using dry sand particles. The particle size and internal friction angle of the bulk particles impact significantly on the deformation of the wall, where the cohesive force among the dispersed particles produced by the compaction effect has a certain influence on the side pressure of the silo wall. During the unloading process, coal particles were easier to obtain an arching phenomenon than dry sand particles. In addition, the number of bulk arching could be significantly reduced under the conditions of the warehouse wall support. The "weak rock stratum" in the surrounding rock plays a major role in controlling the deformation and failure development of the shaft wall. The three-dimensional physical simulation experiment of the transparent shaft wall truly reproduces the field engineering practice, and the physical simulation results are verified by numerical simulation analysis.
为探究动静载荷作用下煤矿竖井煤仓壁的受力、变形、损耗变化规律，确定其力学状态、损耗特性及稳定性，本文创新性地对透明材料竖井煤仓进行三维物理相似试验，并对竖井煤仓采用不同散储材料进行80次装卸煤试验。然后，考虑仓壁支护的存在，讨论了筒仓壁的变形、压力、围岩及流动形态。借助应变片、压力传感器、钻孔窥视仪等多种综合测试系统，分析了卸载过程中竖井壁变形及围岩应力裂纹特征。结果表明，不同分散颗粒对竖井壁应变有显著影响。以煤颗粒作为储存材料时，竖井壁的超压系数比使用干砂颗粒时高出1.95倍。散体颗粒的粒径和内摩擦角对壁体变形影响显著，压实作用产生的分散颗粒间黏聚力对筒仓壁侧压力有一定影响。卸载过程中，煤颗粒比干砂颗粒更容易出现起拱现象。此外，在仓壁支护条件下，散体起拱次数可显著减少。围岩中的“软弱岩层”对竖井壁变形破坏发展起主要控制作用。透明竖井壁三维物理模拟试验真实再现了现场工程实际，物理模拟结果通过数值模拟分析得到验证。
