特厚煤层综放开采多口同时放煤三维实验研究

3D experimental investigation of multi-port caving technology in LTCC with extra-thick seams

为提高特厚煤层综放工作面顶煤回收率及放煤效率,重点研究了多口同时放煤的放煤方式。根据塔山煤矿8222工作面实际情况,进行了多口同时放煤三维相似模拟实验。结果表明:首次放煤时,单口放煤放出体大致呈下窄上宽的漏斗状,多口同时放煤放出体呈现中部宽、两端窄的特点,放煤量呈现单口>双口>三口的现象。首次放煤时,开口数目越多煤岩分界线的斜率越大,对顶煤的扰动范围越大,煤岩分界线的最低点越高,损失的低位顶煤越多,且煤岩分界线最低点基本在该组支架的中心位置;放煤结束后,三口组放出更多支架上方及前方的中低位顶煤,放煤量总体呈现三口>双口>单口的现象。

This paper investigated the multi-port caving technology to improve the top coal recovery and caving efficiency of the longwall top coal caving(LTCC)in extra-thick seams.The 3D drawing experiments are designed based on the actual geological conditions of Panel 8222 in the Tashan Coal Mine.Results indicated that in the initial drawing stage, the drawing body of single-port caving is roughly in the shape of a funnel with a narrow bottom and a wide upper part.The drawing body of multi-port coal caving is characterized by a wide middle and narrow ends, the coal caving volume shows single-port>double-port>three-port.During the initial drawing stage, the larger the number of openings, the greater the slope of the top coal boundary line;the larger the disturbance range to the top coal;and the higher the lowest point of the top coal boundary line, the more low-level top coal is lost.The lowest point of the top coal boundary is basically at the center of the group of supports.When the advance of the panel is completed, the three caving ports release more medium and low-level top coal above and in front of the supports, the coal caving volume generally shows three ports>double ports>single port.