摘要
黄土沟谷区浅埋煤层开采地表非连续性的开裂损害,不仅引发了许多生态环境问题,也加大了生态修复难度,严重威胁着矿区生态安全。浅埋煤层开采地表非连续变形是特殊地质条件下覆岩破坏移动的结果,为更加系统地研究覆岩破坏对地表非连续性损害的影响规律,以陕北安山井田125203工作面为地质原型,采用离散元数值模拟与物理相似材料模拟相结合的方法,模拟分析了覆岩及地表破坏、岩块尺寸分布及力链演化等特征,揭示了覆岩力链演化对块体分布和地裂缝发育的影响规律,阐明了覆岩破坏块体对地表非连续损害的控制效应。研究结果表明:黄土沟壑缓坡地带浅埋煤层开采覆岩垂向变形与水平移动受地形影响较大;覆岩破坏形成双分层块体结构,分层界面距煤层底板11.0 m,下分层块体平均长度小于5.0 m,上分层大于5.0 m,覆岩块体平均长度随岩层至煤层底板距离的增大呈幂指数增长特征,地表块体平均长度由坡底至坡顶逐渐增大;下分层垮落压实的岩块结构和应力集中的力链结构,影响着上分层块体和力链的分布及地裂缝的发育,地裂缝平均间距与上分层应力集中点平均间距基本一致,主沟段顺坡、沟底和逆坡地裂缝平均间距分别约为下分层应力集中点平均间距的1.10倍、0.75倍和1.95倍,分别约为下分层岩块平均长度的2.93倍、2.00倍和5.18倍;“砌体梁”位移模型可以很好地描述下分层底部岩块的下沉移动过程和特征,进而反映覆岩块体的双分层结构特征和地表的损害效应。该研究结果可为黄土沟谷区浅埋煤层开采条件下沉陷控制与修复提供新的科学依据。
The discontinuous cracking damage on the surface of the shallow-buried coal seam mining in loess gully area not only caused many ecological and environmental problems,but also increased the difficulty of ecological restoration,which seriously threatened the eco⁃logical security of the mining area.The discontinuous deformation of the surface of shallow coal seam mining is the result of overlying strata failure movement under special geological conditions.In order to more systematically study the influence law of overlying strata failure on surface discontinuous damage,taking No.125203 working face in Shanbei Anshan minefield as the geological prototype,by using the method of combining discrete element numerical simulation and physical similar mate-rial simulation,the characteristics of overlying rock and surface failure,rock block size distribution and force chain evolution were simulated and analyzed.The law of influence of the evolution of the overlying force chain on the distribution of the blocks and the development of ground fissures was revealed,and the controlling effect of the overlying broken blocks on the discontinuous damage of the surface was clarified.The research results show that the vertical deforma⁃tion and horizontal movement of the overlying strata in the shallow-buried coal seam mining in the gentle slope area of the loess gully area are greatly affected by the terrain.The failure of the overlying strata forms a double-layered block structure.The stratified interface is 11.0 m from the coal seam floor.The average length of the lower stratified block is less than 5.0 m,and the upper stratified block is more than 5.0 m.The average length of the overlying strata block increases exponentially with the distance between the rock strata and the coal seam floor.The average length of the surface blocks increases gradually from the bottom of the slope to the top of the slope.The rock block struc⁃ture of layered caving and compaction in the lower strata and the force chain structure of stress concen
作者
王双明
魏江波
宋世杰
侯恩科
孙涛
WANG Shuangming;WEI Jiangbo;SONG Shijie;HOU Enke;SUN Tao(College of Geology and Environment,Xi’an University of Science and Technology,Xi’an 710054,China;Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation,Xi’an 710054,China;Geological Research Institute for Coal Green Mining,Xi’an University of Science and Technology,Xi’an 710054,China)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2022年第5期1-9,共9页
Coal Science and Technology
基金
国家自然科学基金资助项目(41402308)
榆林市科技计划重大资助项目(6130819001)
陕西省煤炭绿色开发地质保障重点实验室重点基金资助项目(DZBZ2022Z-03)。
关键词
黄土沟谷区
浅埋煤层
覆岩破坏
地表裂缝
颗粒流
loess gully area
shallow-buried coal seam
overburden failure
surface cracks
particle flow
