急倾斜厚煤层综放开采顶煤采出率分布规律研究

Study on top-coal recovery ratio distribution law of longwall top-coal caving mining in steeply thick coal seam

为掌握急倾斜厚煤层综放开采顶煤采出率的分布规律,提高急倾斜煤层资源采出率,采用顶煤放出三维散体相似模拟、数值模拟和现场观测相结合的方法,从顶煤放出体发育形态和煤岩分界面演化特征的角度,深入分析了采出率分布规律和机理。结果表明:急倾斜厚煤层综放开采顶煤采出率沿煤层倾向呈"几"字形分布,顶煤放出体向工作面上端头发育趋势明显,放出体"枣核状"形态和煤岩分界面非对称性的相互作用导致的上下端头煤炭损失差异,是急倾斜厚煤层综放开采顶煤采出率呈"几"字形分布的根本原因,并通过数值计算和现场实测验证了顶煤采出率呈"几"字形分布规律。

In order to grasp the distribution law of top-coal recovery ratio of longwall top-coal caving mining in steeply thick coal seam and improve the coal resource recovery ratio, the 3D loose top-coal drawing experiment, numerical simulation and field test were applied to an- alyze the top-coal recovery ratio from the aspects of shape of top-coal drawing body and the boundary of top-coal. The results showed that the top-coal recovery ratio shows ＂＇rt＂ shape distribution along the dip direction in the 3D loose top-coal drawing experiment; the drawing body had an obvious developing tendency towards the upper end of the working face ; the difference value of top-coal loss at the upper and lower end of working face resulting from the ＂jujube core shape＂ of drawing body and the asymmetry of interface between coal and rock was the root cause of the ＂w＂ shape distribution of top-coal recovery ratio. Such distribution law was also verified by the numerical calcu- lation and the filed test.