为了获得覆岩离层充填后地表沉陷与覆岩破坏的效果,采用点、线结合的办法建立地表移动变形观测站监测地表移动与房屋变形规律,在井下采用仰孔分段注水法及前端泄露式多回路注(放)水系统对东滩煤矿14 308工作面覆岩离层注浆条件下采动导水裂隙带的破坏特征进行了连续探测。结果表明:离层注浆条件下地表的减沉率达到了38.5%,离层注浆时的采动导水裂隙带高度值略高于正常条件下的高度值。综合评价效果为类似矿井的安全开采提供了科学依据。
To understand the surface subsidence and overburden damage after grouting in separate strata layers of overburden,the methods of points and lines were used to locate monitoring stations at surface in order to observe the surface displacement and the building deformation.At the longwall face 14308 of Dongtan coal mine,the grouting in separate strata layers of overburden was conducted using the method of underground up-hole water injection technology by intervals with bore-head leaking multi-loops effusion(discharge) system.The failure characteristic of the water flowing fractured zone was continuously monitored.The results demonstrated that the ratio of surface subsidence reduction reached 38.5% after grouting in separate strata layers.The height of water flowing fractured zone under grouting in separate strata layers condition is slightly higher than that under normal condition.The results provide a useful guidance for the safe exploitation of other mines in similar situations.