顶煤放出率低是急倾斜煤层综放开采所面临的主要问题之一。本文以乌东煤矿北采区45#煤层+575水平工作面为工程背景，采用现场调查、理论分析、实验室实验等方法，开展了急倾斜特厚煤层水平分段综放开采煤矸流动规律及放出控制技术研究。

       综合考虑煤层的地质赋存状况及开采技术条件等因素，通过理论分析得到了合理的分段高度，推导得出了初始放煤阶段和周期放煤阶段的放出体、松动体、煤矸分界线的发育演化规律及其标准方程，并得到了松动体和放出体的关系。根据推导的标准方程计算得出了顶底板三角煤损的计算公式，以及顶煤放出率和含矸率的计算公式；采用相似模拟实验方法，对急倾斜大段高综放开采不同放煤方式及工艺参数进行了研究，验证了理论分析的准确性，同时得到散体顶煤的运动规律，即运动轨迹近似直线，且离放煤口及中轴线越近，颗粒的流速越快。以顶煤放出率、含矸率和放出体发育程度作为衡量指标，得到了优化的放煤方式及工艺参数。采用过量放煤的放出控制原则，得到了当含矸率达到一定范围时的顶煤放出控制指标；采用PFC^2D软件，对优化后的放煤方式及放出控制指标进行模拟，验证了理论分析及相似模拟的准确性，得到了不同含矸率下煤矸分界线演化过程。顶煤位移分布呈现近似椭圆环状，环内位移大小相等，且顶煤越厚，支架对顶煤放出的影响程度越小；分别建立了基于BP和GA-BP神经网络的顶煤可放性预测模型。通过训练和预测得出GA-BP神经网络在收敛速度和预测精度方面均优于BP神经网络，同时通过对比得出采用优化后的放煤方式及放出控制指标，顶煤可放性较好，放出率明显提高。

       本研究为急倾斜煤层大段高综放工作面的安全高效开采提供了参考。

       The low top-coal recovery rate is one of the major problems faced by fully mechanized top-coal caving mining in steeply inclined coal seam. This paper takes the 45# coal seam +575 horizontal working face in the north mining area of Wudong coal mine as the engineering background, and adopts the methods of field investigation, theoretical analysis and laboratory experiments to carry out the research on the flow law and the caving control technology of coal-gangue in the horizontal section fully mechanized top-coal caving mining of steeply inclined ultra-thick coal seam.

       Considering the geological occurrence and mining technical conditions of coal seam, the reasonable sectional height is obtained through theoretical analysis. The development and evolution law and standard equation of the drawing body, loose body and coal-gangue boundary in the initial and periodic coal caving stages are derived, and the relationship between loose body and drawing body is obtained. According to the derived standard equation, the calculation formula of roof and floor triangular coal loss, as well as the calculation formula of top-coal recovery rate and gangue mixed ratio are obtained. The similar simulation experiment method was used to study the different caving methods and process parameters of steeply inclined large section high fully mechanized top-coal caving mining, and the accuracy of theoretical analysis was verified. At the same time, the movement law of the loose top-coal was obtained, that is, the motion trajectory is approximate to a straight line, the closer to the drawing opening position and the central axis position, the faster the particle flow rate.Taking the top-coal recovery rate, gangue mixed ratio and the development degree of the drawing body as the measurement indexes, the optimal coal caving method and process parameters are obtained. Using the control principle of excessive coal caving, the top-coal caving control index is obtained when the gangue mixed ratio reaches a certain range. PFC^2D software is used to simulate the optimized coal caving method and caving control index, verify the accuracy of theoretical analysis and similar simulation, and obtain the evolution process of coal-gangue boundary under different gangue mixed ratio. The displacement distribution of top coal presents an approximate elliptical ring, and the displacement in the ring is equal. The thicker the top coal is, the less the influence of the support on the top coal caving is.The prediction models of top-coal caving capability based on BP and GA-BP neural network are established respectively. GA-BP neural network is better than BP neural network in convergence speed and prediction accuracy. At the same time, through the comparison, it is concluded that the top-coal caving capability is better and the recovery rate is obviously improved by using the optimized coal caving method and caving control index.

       This study provides a reference for safe and efficient mining of large section high fully mechanized top-coal caving working face in steeply inclined coal seam.

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