【作者】 朱卫兵；

【导师】 许家林；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2010， 博士

【摘要】 神东矿区随着开采规模的不断加大,部分区域的第1层主采煤层已经采完,开始回采第2层主采煤层。由于两层煤间距较小,形成了浅埋近距离煤层重复采动的开采条件,在一些特殊的地质采矿条件下,下煤层采场矿压显现异常强烈,工作面曾发生多起支架活柱瞬间大幅下缩甚至压死支架等动载矿压现象,严重威胁了煤矿安全高效生产。论文综合采用理论分析、数值模拟与物理模拟试验、现场实测等方法,就神东矿区浅埋近距离煤层重复采动关键层结构失稳与动载矿压机理进行了深入研究。首次将浅埋近距离煤层覆岩关键层结构分为3类4种,即上煤层已采单一关键层结构、上煤层已采无典型关键层结构和上煤层已采多层关键层结构3类,其中,上煤层已采单一关键层结构包括上煤层已采厚硬单一关键层结构和上煤层已采复合单一关键层结构2种;分析了浅埋上煤层已采单一关键层结构的破断失稳特征与动载矿压发生条件。建立了过沟谷地形上坡段的关键层结构力学模型,据此研究了主关键层受侵蚀影响缺失后无侧向水平压力作用对上煤层已采单一关键层结构稳定的影响,揭示了过沟谷地形上坡段下煤层顶板关键层结构失稳机理,合理解释了浅埋近距离煤层重复采动过沟谷地形上坡时工作面易出现动载矿压的原因。建立了浅埋近距离煤层开采下煤层工作面进、出煤柱阶段关键层破断块体结构的力学模型,分析了上煤层顶板关键层破断块体结构断裂线位置对下煤层关键层结构稳定的影响,揭示了过煤柱阶段上煤层已采单一关键层结构失稳机理,合理解释了工作面出煤柱时易发生动载矿压的原因。根据研究成果确定了大柳塔煤矿活鸡兔井三盘区上煤层已采单一关键层结构条件下工作面过沟谷地形时所需合理的支架工作阻力。应用理论研究成果提出了大柳塔煤矿近距离煤层重复采动关键层结构失稳控制与防范措施,通过危险区域预测、周期来压位置预测及工作面支护质量监测等保障了21305、21306两个工作面的安全回采,取得了显著的应用效果和经济效益。更多还原

【Abstract】 With the successive exploration of Shendong mining area, the exploration of the 2nd main mineable coal seam has been started in some area where the 1st seam has been explored. Due to the close distance of the two seams, the specific condition of repeated mining in close distance shallow seams has formed, specifically, in some particular area the strata behaviors of the lower seam are intense, and this can be seen from the multiple cases of instant descending of support active column and supports crushing, which has severely threatened the mine safety and its high efficiency production. Further research on instability mechanism of key stratum structure in close distance shallow seams repeated mining were studied using theoretical analysis, numerical simulation, physical simulation, field test etc.Key stratum of close distance shallow seams were classified into three kinds or four forms for the first time, that is the single key stratum structure including the thick and hard single key stratum structure and composed single key stratum structure, no typical key stratum structure, multiple key stratum structure while the upper seam has been excavated; instability characteristics of single key stratum in shallow seams while the upper had been excavated and its occurrence condition were analyzed. Uphill mechanical model was established, through which the influence of horizontal side force on the stability of single key stratum in shallow seams while the upper had been excavated and the main key stratum had been eroded was studied, the instability mechanism of single key stratum while the upper had been excavated and the surface was gully was revealed, influencing factors of dynamic strata behaviors were summarized, The key stratum structure mechanical model while crossing the pillar in close distance shallow seams was established, through which the influence of movement of key stratum block of upper seam on the key stratum stability of lower seam was analyzed, the instability mechanism of single key stratum while the upper seam had been excavated and crossing the pillar was revealed as well.Determining the suitable support resistance in Daliuta Mine Huojitu adit under the condition of single key stratum while the upper had been excavated. Consequently, the precaution measures of instability of key stratum in close distance shallow seams repeated mining of Daliuta Mine and Bulianta Mine were proposed, which has obtained remarkable economic effects.更多还原