浅埋煤层不同开采方法破坏特征及稳定性分析

Failure Characteristics and Stability Analysis of Different Mining Methods for Shallow Buried Coal Seams

  • 摘要: 针对西部矿区浅埋软岩煤层开采引发地表塌陷、水土流失及生态破坏等问题,以内蒙古鄂尔多斯地区浅埋煤层为研究对象,通过相似模拟与数值模拟相结合的方法,系统研究了垮落法、留大煤柱条带充填法及不留大煤柱全采全充法的覆岩破坏特征与稳定性规律。基于关键层理论,揭示了不同开采方法下覆岩破坏模式。研究结果表明:三种开采方法对应的最大地表下沉值分别为2850 mm、1150 mm和350 mm,导水裂隙带高度分别为68.5 m、32.1 m和15.8 m。在全采全充法中存在的二次岩层扰动现象具有明显的时空特征:两次扰动间隔7~14 d,位移增量达15~45 mm,应力增量达0.5~1.2 MPa。研究结果可为西部生态脆弱区煤层绿色开采提供理论参考。

     

    Abstract: Aiming at the problems of surface collapse, soil erosion, ecological damage and others caused by shallow buried soft rock coal seam mining in western China, taking the shallow buried coal seams in Ordos region of Inner Mongolia as the research object. Through a combination method of similarity simulation and numerical simulation, the failure characteristics and stability laws of overburden rock of the collapse method, the strip filling method with the residual large coal pillars, and the full mining and filling method without large coal pillars are systematically studied. Based on the key layer theory, the overburden rock failure modes under different mining methods are revealed. The research results show that the maximum surface subsidence values corresponding to the three types of mining methods are 2850 mm, 1150 mm, and 350 mm, respectively, and the heights of the water conducting fissure zones are 68.5 m, 32.1 m, and 15.8 m, respectively. The secondary rock strata disturbance phenomena in the full mining and full filling method have obvious spatiotemporal characteristics: the interval between the two disturbances is 7-14 d, the displacement increment reaches 15-45 mm, and the stress increment reaches 0.5-1.2 MPa. The research results can provide theoretical reference for coal seam green mining in ecologically fragile areas in the western region.

     

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