Structure and deformation measurements of shallow overburden during top coal caving longwall mining

Mining induced pressures are strong and overburden failure areas are large in top coal caving longwall mining, which constrains high production and safety mining. By employing the combination of the full view borehole photography technique and the seismic CT scanner technique, the deformation and failure of overlying strata of fully mechanized caving face in shallow coal seam were studied and the failure development of overburden was determined. Results show that the full view borehole photography can reveal the characteristics of strata, and the seismic CT scanner can reflect the characteristics of strata between the boreholes. The combined measurement technique can effectively determine the height of fractured and caved zones. The top end of the caved zone in Yangwangou coal mine employing the top coal caving longwall mining was at the depth of 171 m and fractured zone was at the depth of 106-110 m. The results provide a theoretic foundation for controlling the overburden strata in the shallow buried top coal caving panel.

放顶煤长壁开采浅覆岩结构与变形研究

采用全景式钻孔摄影技术可以反映地层特征,地震CT扫描仪能较好地反映井间地层特征,两种技术方法相结合研究长壁开采在浅层综采工作面中覆岩层的变形破坏规律。结果表明,可以有效地确定破碎带和崩落带的高度。最后通过实测验证得到顶端深度为171 m,破碎带深度106-110 m之间,研究结果可作为控制浅埋放顶煤盘区覆岩的依据。