高强度重复开采覆岩与地表移动机理

Overburden and Surface Movement Mechanism of High Intensity Repeated Mining

为了给神东等大型煤炭生产基地生态修复和“三下”开采提供理论和技术支持,以实测方式为基础,深入研究了高强度重复开采地表移动特征和机理。分别对老采空区下开采、工作面隔离煤柱下开采、跨老采空区和隔离煤柱下开采这3种工况布设地表移动观测线,开展快速密集监测,采集了丰富的地表移动数据。结合井下推进过程,通过数据分析,获得了不同时期下沉和水平移动值,绘制了地表移动曲线时序图。研究表明:隔离煤柱对地表下沉的发展过程具有阻碍性、带动性和活化性等特征,水平移动方向对井下推进方向具有追随性等现象。据此建立了高强度重复采动条件下形成的块体岩层结构模型,分析了块状岩体在井下推进过程中平衡—旋转平移—再平衡的运动过程,揭示了地表移动实测曲线形态背后的岩层移动机理。研究成果可为该矿区或类似矿区开采沉陷预计模型建立和生态环境修复治理提供参考。

In order to provide theoretical and technical support for ecological restoration and the mining of coal under buildings,railroads and water bodies,in large coal production bases such as Shendong coal mining area,the characteristics and mechanism of surface movement in high-intensity repetitive mining were deeply studied based on the field observation method.Firstly,surface movement observation lines are set for mining under old goaf,mining under coal pillar,mining under old goaf and coal pillar.Rapid and intensive monitoring is carried out to collect abundant surface movement data.Then,the subsidence and horizontal movement values in different periods were obtained through data analysis,and the time series of surface movement curve was drawn.Through curve analysis,it is found that coal pillar has the characteristics of hindrance,driving and activation to the development process of surface subsidence.The driving relationship between the advancing process and the shape of the horizontal movement curve had been found:the direction of the horizontal movement follows advancing direction of the working face.Finally,the block rock structure model under the condition of high intensity repeated mining is established,and the movement process of the block-rock mass in the process of underground advancing is analyzed.The mechanism of rock strata movement behind the measured curve of surface movement is revealed.The study results can provide technical support for the establishment of mining subsidence prediction model and ecological environment restoration and management in this mining area or similar mining areas.