通过神东矿区补连塔煤矿31401工作面内部岩移的地面钻孔原位观测与地表沉陷观测的对比研究,就覆岩主关键层运动对地表沉陷的影响进行实测研究。研究结果表明:厚47.01m的粉砂岩主关键层控制了上覆基岩直至地表的移动变形,上覆岩层的运动随主关键层破断出现周期性跳跃变化;受主关键层的控制作用,地表沉陷测站观测时间间隔长短显著影响了测点的下沉速度曲线,观测时间间隔越短,其对应的下沉速度曲线呈现的周期跳跃性变化越强;观测时间间隔越长,其对应的下沉速度曲线更为均化。因此,在浅埋煤层开采中,为了准确反映地表下沉的动态过程,应该缩短观测时间间隔,才能正确掌握采动覆岩内部移动与地表沉陷的内在联系,推动开采沉陷预计的发展。
Based on the contrastive analysis between the in-situ test on interior rock movement and surface subsidence observation at working face No.31401 of Bulianta coal mine in Shendong mining area, the influences of overburden primary key stratum on surface subsidence are researched. The results indicate that the movement and deformation of overburden strata and surface are controlled by the primary key stratum, which is siltstone with the thickness of 47.01 m; and the movement of overburden strata changes periodically with the breakage of primary key stratum. Controlled by the primary key stratum, the subsidence velocity curves of the measuring points are influenced markedly by the measuring interval. The shorter the measuring interval is, the more obvious the periodical jumping change phenomenon of corresponding subsidence velocity curve is. Otherwise, the subsidence velocity curve is more even. Therefore, the measuring interval should be shortened in order to reflect the dynamic process of surface subsidence exactly in shallow coal seam mining; and then the inherent relationship between interior rock movement and surface subsidence can be realized correctly, which can promote the development of surface subsidence prediction.