1. College of Resource and Safety Engineering,China University of Mining and Technology (Beijing),Beijing　 100083,China;2. Coal Industry Engineering Research Center of Top-coal Caving Mining,Beijing　 100083,China

从理论上描述了综放开采顶煤放出体的形态及影响因素,引用散体介质力学中的Berg-mark-Roos模型(B-R模型),考虑了综放支架对顶煤放出过程及放出体的影响,通过散体顶煤三维放出相似模拟和PFC3D数值模拟,得到了重力加速度修正系数K,对B-R模型进行了改进,改进后的模型可以准确描述顶煤放出过程,得到了顶煤放出体理论形态。支架掩护梁-散体顶煤和顶煤-顶煤之间摩擦因数f的差异会导致顶煤放出体左右两侧散体颗粒临界运移角度θG的不同,使放出体向支架前方超前发育,这一放出体理论形态与BBR研究中顶煤放出体呈"切割变异椭球体"的形态相吻合,使用该理论模型可预测不同顶煤厚度条件下的放煤时间。

This paper theoretically describes the shape of drawing body in LTCC and its influencing factors. The Berg- mark-Roos granular mechanical model ( B-R model) was adopted with the consideration on the influence of shield beam on drawing process and drawing body. The B-R model was modified by introducing the correction coefficient of gravity acceleration (K) and K was obtained through the experimental simulation and PFC3D numerical simulation. The modified model can precisely describe the drawing process and the theoretical shape of drawing body can be calculated by using this model. The difference value of the friction coefficients between the support shield beam and granular top- coal can lead to the different values of maximum migration angle θG ,and the different θG is the basic reason for the drawing body’s characteristic of developing toward the front of the support. This conclusion conforms to the shape of cut-variation ellipsoid proposed in BBR system. This model can accurately predict the drawing time in different heights of coal seams.

国家自然科学基金煤炭联合基金资助项目(U1361209)；国家重点基础研究发展计划(973)资助项目(2013CB227903)；

Wang Jiachen,Song Zhengyang,Zhang Jinwang,et al. Theoretical model of drawing body in LTCC mining[J]. Journal of China Coal Socie- ty,2016,41(2):352-358.