Xinjiang Energy Co. Ltd, National Energy Group
College of Safety and Environmental Engineering, Shandong University of Science and Technology

近直立特厚煤层由于其特殊开采方式,导致采空区的覆岩垮落与裂隙发育规律较水平煤层不同。利用相似材料模拟试验研究了近直立煤层采空区覆岩垮落规律,然后利用PFC3D软件模拟了不同水平分段开采稳定后的地表沉降和裂隙发育情况,分析了空隙率演化规律,并进一步探究了地表沉降规律。相似材料模拟试验发现,随着分段开采的进行,上覆岩层逐渐垮落,首先形成“U”形区域,最终形成“V”形的垮落结构;随着开采的进行,采空区两端所留的少量空间逐渐消失,采空区裂隙与地表连通,形成采空区漏风通道;采空区的空隙率稳定在0.30~0.65,顶、底板侧裂隙的空隙率逐渐增加,最终稳定在0.30左右;垮落后地表沉降范围宽度由92.93m缓慢增加至100.16m,深度由27.85m大幅增加,最终稳定在101.63m。研究结果可为近直立煤层的开采设计及安全生产提供参考。

Due to the special mining mode of near vertical ultra-thick coal seam, the development law of overburden caving and fissure in goaf is different from that of horizontal coal seam. Similar material simulation experiment was used to study the caving law of overlying rock in gob area of near vertical coal seam. PFC software was used to simulate the surface settlement and fracture development after stable mining in different level sections. The porosity evolution law was quantitatively analyzed, and the surface settlement law was further explored. The simulation experiment of similar materials found that with the progress of segmented mining, the overlying strata gradually collapsed, forming firstly a “U-shaped” area and then a “V-shaped” caving structure. The numerical simulation results show that with the progress of mining, the small amount of space left at both ends of the goaf gradually disappears, and the cracks in the goaf are connected with the surface, forming air leakage channels in the goaf. The caving law of overlying rock is consistent with the results of similar material experiments. The porosity of the goaf was stable between 0.30~0.65, and the porosity of the cracks on the top and bottom sides gradually increased, and finally stabilized at about 0.30. After the collapse, the width of the surface settlement gradually increased from 92.93 m to 100.16 m, and the depth greatly increased from 27.85 m, and finally stabilized at 101.63 m. The research results can provide reference for the mining design and safe production of near vertical coal seam.

2018年新疆维吾尔自治区引进高层次人才天池百人计划项目(新人社函[2019]39号)