浅埋高强度开采地表及覆岩破坏特征--以神东矿区为例

采用现场实测与理论分析的方法对神东矿区地表非连续变形及地表移动持续时间进行了研究。阐释了高强度开采的内涵,并提出以地表最大下沉速度、采动损害程度及工作面来压强度作为判断指标。总结了神东矿区基岩全厚切落式和基岩部分破坏式2种岩层移动类型。分析总结了神东矿区地表移动以伴随非连续变形为主要特征的高强度开采规律:地表最大下沉速度达700mm/d,非连续变形以裂缝与台阶为主;采动裂缝以裂缝带形式发育,主裂缝间距与工作面周期来压步距基本一致,最前裂缝带内主裂缝滞后角约79.8°,地表最宽裂缝滞后角58.2°;裂缝发育条数及宽度与表土性质密切相关,风积沙区裂缝宽度一般小于30mm,黏性表土区一般大于50mm,裂缝宽深近似线性相关。本文可为类似开采条件下采动损害控制、地表环境治理、开采设计提供参考。

Surface and overburden damage characteristics in shallow-buried coal seam with strong disturbance mining--Taking Shendong coal mine district as an example

Using field measurement and theoretical analysis studies surface discontinuous deformation and lasting time of surface movement in Shendong mining district in this paper. It describes the connotation of strong disturbance mining, and proposing in accordance to the maximum surface subsidence velocity, extent of damage and weighting intensity of mining face as a judge index. It summarizes the two strata movement types of bedrock falling with whole thick and partial destruction in Shendong mining district. It analyzes and summarizes the laws of strong disturbance of surface movement accompanied with discontinuous deformation as the main feature in Shendong mining district. Firstly, maximum surface subsidence velocity is 700mm/d; Then, discontinuous deformation is mainly composed of cracks and steps, mining cracks developed in the form of crack zone, the spacing of the main crack is the basically same as the periodic weighting interval of face, the main crack lag angle is about 79.8° in the foremost crack zone, the widest surface crack lag angle is 58.2°; Finally, the number and width of crack development are closely related to soil properties, so crack width is generally less than 30mm in aeolian sand area and is generally greater than 50mm in the viscous surface area, the width and depth of crack are approximate linear correlation. This paper can provide a reference for mining damage, surface environmental control and mining design under similar mining conditions.