摘要:
深部煤与瓦斯突出发生机理必然与浅部存在显著差异，将辽宁某矿12煤层型煤作为研究对象，采用自主研发的可同时施加轴压、围压、孔隙压的煤与瓦斯突出全过程模拟装置，以轴压模拟上覆岩层应力作用，围压模拟围岩应力作用，孔隙压模拟气体压力，进行了埋深分别为1 100、1 300、1 500、1 700、1 900、2 100、2 300和2 500 m的高地应力条件煤与瓦斯突出模拟试验并验证了其可靠性，定义单位气体压力突出煤粉质量为相对突出强度，得到相对突出强度、临界气体压力与埋深关系规律。结果发现：① 深部煤与瓦斯突出特征与浅部存在明显差异，突出煤粉分布呈喇叭形，主要集中在15～25 m内，突出煤粉质量占比达52%～63%；② 深部煤与瓦斯突出相对突出强度和临界气体压力变化趋势具有2阶段特征，存在分界深度为1 700 m，埋深1 100～1 700 m为剧烈变化阶段，埋深1 700～2 500 m为缓慢变化阶段；③ 深部煤与瓦斯突出瞬时气体压力具有“台阶效应”，台阶效应持续时间随埋深增大而减小，在埋深2 500 m时台阶效应消失，说明此时煤与瓦斯突出具有更大的突出危险性。
Abstract:
The occurrence mechanism of deep coal and gas outburst must be significantly different from the shallow part. Taking 12 coal seam in a Liaoning mine as the research background, using the self-developed simulation device for the whole process of coal and gas outburst that can apply axial pressure, confining pressure and pore pressure at the same time, the axial pressure simulates the stress effect of the overlying rock, the confining pressure simulates the surrounding rock stress, and the pore pressure simulates the gas pressure. Simulation tests of coal and gas outburst under high in-situ stress conditions with buried depths of 1 100, 1 300, 1 500, 1 700, 1 900, 2 100, 2 300 and 2 500 m were carried out and their reliability was verified. The relationship between relative prominent strength, critical gas pressure and buried depth is obtained. The results show that: ① The characteristics of coal and gas outbursts in deep parts are obviously different from those in shallow parts, and the distribution of prominent coal powder is trumpet-shaped, mainly concentrated in the range of 15 m-25 m, and the mass proportion of outburst coal powder reaches 52%-63%; ② The relative outburst strength and critical gas pressure change trend of deep coal and gas have two stages. There is a boundary depth of 1 700 m, a violent change stage at a buried depth of 1 100 m-1 700 m, and a slow change stage at a buried depth of 1 700-2 500 m; ③ The instantaneous gas pressure of the deep coal and gas outburst has a “step effect”. The duration of the step effect decreases with the increase of the buried depth, and the step effect disappears when the the buried depth is 2 500 m, indicating that the coal and gas outburst have a greater outburst risk at this time.
百度学术
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