深部硬煤掘进工作面煤与瓦斯突出机制探讨

Discussion on mechanism of coal and gas outbursts in face of hard coal roadway tunneling in deep coal seam

为深入探讨硬煤的煤与瓦斯突出机制,对深部硬煤掘进工作面煤与瓦斯突出的相关理论和模型试验进行研究。根据断裂力学、岩石力学及煤与瓦斯突出有关理论,提出深部开采过程中硬煤掘进工作面薄板理论假设,并将该理论应用于深部硬煤掘进工作面煤与瓦斯突出模拟试验研究。对硬煤掘进工作面薄板理论分析,认为工作面尺寸、煤的弹性模量、围岩侧压系数、瓦斯压力等因素对硬煤掘进工作面突出具有较大影响。试验结果表明,在围岩应力、煤的坚固性系数较大的情况下,硬煤突出临界条件主要受围岩应力、煤的弹性模量、围岩侧压系数及工作面尺寸等因素影响,而受瓦斯压力影响相对较小;在围岩应力、试样的坚固性系数较大且煤的弹性模量和侧压系数稳定不变的情况下,发生突出的临界轴向应力随模拟工作面尺寸增大而近似呈线性减小。试验结论基本符合本硬煤突出薄板模型理论公式,在一定程度上验证了硬煤掘进工作面煤薄板模型理论及硬煤掘进工作面突出机制假设。

The related theory and model tests of coal and gas outbursts in the face of hard coal roadway tunneling in the deep coal seam were studied to explore the coal and gas outburst mechanism of hard coal. Based on fracture mechanics, rock mechanics and theory of coal and gas outburst, a hypothesis of thin plate theory of coal roadway tunneling in the deep coal seam was proposed, and used to the model tests. The analysis results of thin plate theory of coal roadway tunneling in the deep coal seam show the size of working face, elastic modulus, the coefficient of lateral pressure and gas pressure have a great influence on coal and gas outbursts in the face of hard coal roadway tunneling in the deep coal seam. The results of model tests show that under the condition of large stress of surrounding rock and the consistence coefficient of coal, the critical conditions of coal and gas outbursts in the face of hard coal roadway tunneling in the deep coal seam are affected mainly by the surrounding rock stress, the elastic modulus, the coefficient of lateral pressure and the size of working face, and less affected by gas pressure. Under the condition of the large stress of surrounding rock, the large consistence coefficient of coal, the constant elastic modulus and the constant coefficient of lateral pressure, the critical axial stress of the model tests decreases approximate linearly with the increases of the working face size. The results of the model tests basically conform to the thin plate theory of coal roadway tunneling in the deep coal seam, which verify the hypothesis of thin plate theory of coal roadway tunneling in the deep coal seam.