神东保德浅埋煤层覆岩裂隙带高度数值指标判别阈值及采高效应

Threshold value of numerical index and mining height effect of overburden fracture zone height in Shendong Baode shallow coal seam

  • 摘要: 覆岩裂隙带高度是研究覆岩变形破坏的重要指标,而现有单一指标无法反映空间采场围岩不同空间部位的破裂程度。本文以神东典型浅埋条件保德矿81505工作面为研究背景,基于室内实验对岩体破裂度进行了RFD阈值划分并构建相似模型和数值模型;基于围岩破坏度指标RFD提取了数值模拟中的最大破坏深度,并对比相似模拟结果研究了覆岩采动裂隙带发育高度规律及随采高的变化规律。结果表明,围岩破坏度指标RFD可以很好地评测神东典型浅埋条件下采动裂隙带的发育特征,裂隙带发育高度随采高的增大而持续增高,但增长速率逐渐减小。本研究为裂隙带分布破坏特征、矿压显现及安全开采提供理论支撑及技术依据。

     

    Abstract: The height of overburden fissure zone is an important index to study the deformation and failure of overburden, but the existing single index can not reflect the fracture degree of surrounding rock in different space parts of stope. Based on 81505 working face of Baode Mine with typical shallow burial conditions in Shendong, the unification of coal sample damage degree and index RFD (Rock Failure Degree) is completed by laboratory experiments, and a similar model and a numerical model are constructed. Based on the index RFD, the maximum destructive depth in numerical simulation is extracted, and the law of development height of overburden mining fissure zone and its variation with mining height are studied by comparing similar simulation results. The results show that the index RFD can well assess the development characteristics of mining fissure zone under typical shallow burial conditions in Shendong. And the development height of fissure zone continuously with the increase of mining height but the growth rate decreases gradually. The research in this paper provides theoretical support and technical basis for distribution and destruction characteristics of fractured zones, occurrence of rock pressure and safe mining.

     

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