School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou, Jiangsu, China.
School of Environmental and Civil Engineering, Jiangnan University, Wuxi, Jiangsu, China.
PLoS One. 2021 May 5;16(5):e0250961. doi: 10.1371/journal.pone.0250961. eCollection 2021.
In this study, dynamic compaction method was used to treat the gangue hill of the Xinglongzhuang coal mine in China, and the deep compaction of deep coal gangue was examined. The crushing characteristics and improving depth of coal gangue filling under different dynamic compaction conditions were determined. Dynamic compaction tests with different tamping energy were performed to improve the coal gangue filling. In addition, dynamic penetration tests and the foundation bearing capacity were conducted. The relationship between the tamping energy and improvement was investigated, and the optimum tamping energy, number of tamping blows, improving depth, and other dynamic compaction parameters and filling bearing characteristics were obtained. The field test results show that with increasing number of tamping blows, compaction induced deformation gradually decreased and begins to stabilize, while the optimum number of tamping blows increases with increasing ramming energy. The optimum number of tamping blows is in the range 9-11, and the effective coal gangue improving depth is in the range 6-8m, when the tamping energy is greater than 3000 kN.m. The gradation improved, and the weight percentage of the particles smaller than 4.75 mm was larger than 50%, resulting in better physical and mechanical behavior of the coal gangue filling. The coal gangue filling bearing capacity and anti-deformation ability increase with increasing tamping energy. The coal gangue filling bearing capacity reached at least 350 kPa after being improved by dynamic compaction with a tamping energy greater than 3000kN.m.
本研究采用强夯法对中国兴隆庄煤矿的煤矸石山进行处理，考察了深部煤矸石的深层强夯效果。确定了不同强夯条件下煤矸石填充体的破碎特性和改良深度。采用不同夯实能量进行强夯试验，以提高煤矸石填充体的质量。此外，还进行了动力触探试验和地基承载力试验。研究了夯实能量与改良效果之间的关系，得出了最优夯实能量、夯实次数、改良深度等强夯参数以及填充体承载特性。现场试验结果表明，随着夯实次数的增加，压实诱导变形逐渐减小并趋于稳定，而最优夯实次数随夯实能量的增加而增加。当夯实能量大于 3000 kN·m 时，最优夯实次数在 9-11 次之间，有效煤矸石改良深度在 6-8m 之间。级配得到改善，粒径小于 4.75mm 的颗粒重量百分比大于 50%，从而改善了煤矸石填充体的物理力学性能。随着夯实能量的增加，煤矸石填充体的承载力和抗变形能力均有所提高。经大于 3000kN·m 夯实能量强夯处理后，煤矸石填充体的承载力至少达到 350kPa。
