由于放煤口布置方向的差异，放矿椭球体理论的适用条件与低位放煤综放开采的放煤过程有本质差异，因此基于模拟试验、FLAC 计算、离散元模拟计算和现场观测，本文提出了散体介质流理论模型，揭示了低位综放开采中顶煤流动与放出的真实过程，并且成功地指导了现场放煤工艺与参数的确定。

There are a lot of uncertainties in the mining engineering, and they make a notable impact on the engineering. The uncertainties of the physical and mechanical properties of geotechnical mass, the surrounding rock stability, the nature condition, the equipment operation, the personnel and the external environment are proposed and described in this paper. The stochastic analysis should be widely used for considering the impacts of the uncertainty on the mining engineering. The economical risk analysis and the stochastic index system should also be set up in the mining engineering.