复合煤层群双重卸压应力时空演化规律研究

发布时间：2018-10-24 13:07

【摘要】：为探索复合煤层群保护层开采过程中,在双重卸压条件下首采保护层和次采保护层过程中卸压特征的不同,采用相似材料实验、计算机数值模拟研究双重卸压覆岩裂隙发育、变形特征和应力分布时空演化规律,通过对比分析表明:在二次保护层开采条件下,覆岩部分裂隙经历了二次扩张,压实,吻合,部分裂隙在空间上往深部发育,裂隙带高度范围增加。应力在首采保护层应力状态的影响下进行再分布,随开采过程形成了5个应力分布区域,分别为工作面超前应力集中区、卸压区、压实区、采空区后方应力集中区、原岩应力区。双重卸压下采空区两端卸压效果更为显著,超前应力集中系数较首采保护层要高,采空区压实速度较首采保护层快,同时被保护层卸压程度和范围均显著增加。
[Abstract]:In order to explore the difference of the pressure relief characteristics between the first mining cover and the secondary mining protection layer in the process of mining the protective layer of the composite coal seam group under the condition of double pressure relief, similar material experiments and computer numerical simulation are used to study the development of the fracture in the double pressure relief overburden rock. The characteristics of deformation and the temporal and spatial evolution of stress distribution show that under the condition of secondary protective layer mining, some cracks of overburden rock undergo secondary expansion, compaction, coincidence, and some cracks develop deep in space. The height range of fracture zone increases. The stress is redistributed under the influence of the stress state of the first mining protection layer, and five stress distribution areas are formed with the mining process, which are the leading stress concentration area, the relief zone, the compaction area and the rear stress concentration area of the goaf, respectively. Original rock stress zone. Under double pressure relief, the pressure relief effect of both ends of goaf is more remarkable, the stress concentration factor is higher than that of the first mining protection layer, the compaction speed of goaf is faster than that of the first mining protection layer, and the pressure relief degree and range of protected layer increase significantly.
【作者单位】：湖南工学院安全与环境工程学院;煤炭资源与安全开采国家重点实验室;中国矿业大学安全工程学院;
【基金】：国家重点基础研究发展计划资助项目(2011CB201205) 教育部新世纪优秀人才支持计划资助项目(NCET-12-0959) 安全工程教育部第一类特色专业建设点资助项目(TS12328)
【分类号】：TD712.6

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