特厚煤层煤矸互层复合顶煤体冒落特征研究

为了掌握特厚煤层综放开采煤矸互层复合顶煤体冒落特征，保证放煤工艺合理性和高顶煤回收率，以特厚煤层复合顶煤体综放开采为现场实际条件，采用实验室试验、数值模拟、现场观测等方法，分析了复合煤岩体变形破坏和强度特征，揭示了含矸顶煤体放出过程架间成拱、煤矸分界、放出规律，获得了煤矸块度体积与重量分布特征，结果表明：煤岩比例变化对煤岩整体破坏形态影响明显，复合煤岩体的破坏比单一介质块度小，单架顺序放煤量与放出率低值区和高值区之比约为1∶3，复合煤岩体放出块度体积与重量符合正态分布，煤矸块体长度小于40cm的占比为66%，但其重量占比小于15%，特厚煤层含矸顶煤体提高顶煤回收率的主要方向为提高长度为40～100cm块体的放出效率。

Research on caving characteristics of coal gangue interbedded composite top coal body in extra-thick coal seam

In order to grasp the characteristics of coal gangue interbed composite top coal caving in ultra-thick coal seam mining, and ensure the rationality of coal caving technology and high top coal recovery rate, this paper takes ultra-thick coal seam composite top coal mining as actual site conditions, analyzed the deformation, failure and strength characteristics of the composite coal and rock mass by using laboratory tests, numerical simulations, and on-site observations, and revealed the arching of the gangue-bearing coal body during the caving process, the gangue boundary and the caving law, and obtained the coal the distribution characteristics of gangue volume and weight. The results show that: the change of coal-rock proportion has obvious influence on the overall failure form of coal and rock, the damage of composite coal and rock mass is smaller than that of single medium, and the degree of development of coal mass fissures is higher, the greater the difference between the triaxial compressive strength and the uniaxial compressive strength of the composite coal rock mass, the greater the overall strength of the top coal body increases, the greater the probability of top coal arching, the larger the scale of the balance arch, and the orderly placement of single frames. The ratio of coal quantity to low-value area and high-value area of the release rate is about 1:3. The volume and weight of the composite coal rock mass are in accordance with the normal distribution, and the proportion of coal gangue blocks less than 40cm in length is 66%, but Its weight accounted for less than 15%. The main direction of the extra-thick coal seam containing gangue to increase the recovery rate of the top coal is to increase the discharge efficiency of blocks with a length of 40-100 cm.