综放工作面顶煤放出体形态理论研究.doc

综放工作面顶煤放出体形态理论研究 宋晓波 王鹏宇 （山西潞安集团余吾煤业有限责任公司 长治 046031） 摘 要：为了研究顶煤放出体形态，本文将破碎的顶煤看做随机流动的松散介质，利用PFC2d离散元计算软件建立了放顶煤横向剖面的二维模型，通过离散元迭代法计算出顶煤放出体形态。以放出体边界小球坐标为基础，对随机介质理论的二维方程进行数据拟合，得了二维顶煤放出体函数。在二维模型的基础上，假设在横向剖面和纵向剖面两个方向上顶煤流动是相互独立的，对随机介质理论的三维方程进行数据拟合，得出了三维顶煤放出体函数函数图形与模拟放出体形状基本一致，he Drawnbody Shapes of the Top Coal Drawning SONG Xiaobo WANG Pengyu (Yuwu Coal Industry Comparny of Lu’an Environmental Energy Development Co. Ltd. Changzhi 046031 China) Abstract：In this paper，the broken top-coal was regarded as random flowing loose medium. By using the PFC2d, the two-dimensional model in transverse section is established, and the shapes of drawn top-coal can be worked out through discrete element iteration method. Based on the boundary spherule coordinate, the two-dimensional function of drawn top-coal is determined by carrying on data fitting to the two-dimensional equation of random medium theory. The top-coal drawing is a three-dimensional process. The paper assumes that the processes of top-coal drawing are mutual independent in transverse section and longitudinal section, according to the boundary spherule coordinate, the three-dimensional equation of drawn top-coal could be determined by carrying on data fitting to the to the three-dimensional equation of random medium theory, image and the simulated drawn top-coal shapes being basically identical. It would be of some guiding significance to the determination of caving coal mining parameters. Keywords: fully mechanized caving face; random medium theory; drawnbody of the top coal; discrete element 1、引言 近三十年来，随着综放开采技术在我国各大矿区的广泛应用，国内专家学者、技术人员对顶煤放出规律开展了大量研究工作。在顶煤放出规律研究中，始终以椭球体理论为基础[1-3]，但是椭球体理论对放出体形态的多态变化，不能完整地表达，其定量计算的精度不高。近年来，许多学者将顶煤放出过程看做是松散体的流动过程[4-9]，取得了一定成果，但在顶煤放出体形态方面，还需要进一步研究。 随机介质理论就是将散体简化为连续流动的随机介质，运用概率论方法研究散体移动过程而形成的理论体系。“随机介质”最早是由波兰学者Litwiniszyn在上个世纪6O年代初研究岩层的移动规律时提出来的，他将松散岩石看作松散介质，将松散介质的移动过程看作一个随机过程，并给出了理想散体随机移动模型[10-11]。受上述思想的启发，东北大学的王永嘉教授对这一领域进行了深入研究[12]。随后，东北大学任凤玉教授在前人的基础上建立了理想散体移动模型来研究金属矿山放矿规律，并运用数学归纳法、求极