以45°急斜特厚煤层综放工作面顶板煤岩稳定性控制为目标,采用现场调查、数值计算和现场监测等方法,综合分析了开采扰动影响下顶板应力和运移规律及演化过程,实施了分段缷压控制技术措施。研究表明:在开采扰动下,急倾斜煤层顶板岩体与煤层共同变形,相互影响,应力集中区约为30 m,在顶板倾斜长度30 m附近应力与变形显著,顶板岩体动态变形呈现"V"结构,在倾斜长度20 m左右应力释放不充分,易诱致动力灾害。现场采用了能反映电磁波与岩体破碎特征对应关系的井下智能雷达探测,评价结果表明,分段卸压技术措施实施后,综放面顶板岩体破碎连续,随工作面推进不会造成顶板大面积悬空,这为现场安全开采提供了科学依据。
This paper focuses on the stability control of roof at 45° of extremely steep and thick coal seams excavated by fully mechanized top-caving. We adopted a hybrid methodology including in-situ investigation,numerical simulation,and site monitoring. Mechanisms of both stress evolution and roof migration have been totally analyzed under excavated disturbance. Finally,control measurement of segmentation unloading was implemented for roof stabilization. Research results indicate that coal-rock masses of the roof are deformed in common,and Scope of stress concentration zone is 30 m approximately. Particularly,the stress and deformation are both obvious in 30 m inclination direction. Moreover,the deformation of roof presents "V"shape structure and residual stress does not release sufficiently in 20 m inclination direction easily inducing dynamic hazards. With in-situ penetrating radar presenting the relation between electromagnetic wave and broken trait of rock masses,the roof are broken sufficiently without a largescale roof hanging after segmentation unloading,which would provide scientific basis for safe mining.