深井瓦斯煤层采动扩容致灾力学机理

发布时间：2018-03-13 08:01

本文选题：扩容致灾　切入点：采动应力　出处：《煤炭学报》2015年01期 　论文类型：期刊论文

【摘要】：为揭示深井瓦斯煤层扩容致灾的内在力学机理,从宏观和细观角度对含瓦斯煤扩容过程的力学特征进行了系统研究。研究表明,受采动应力作用的工作面煤层存在扩容缓变和扩容急变两种力学状态;扩容缓变区煤层累计扩容量缓慢增加、瓦斯压力随采动应力增大而增大;扩容急变区煤层累计扩容量激增导致煤层瓦斯压力突变降低,易诱发动力灾害。含瓦斯煤扩容行为致使瓦斯压力突变,初始瓦斯压力增大导致扩容应力临界值降低、煤体扩容率明显增加、扩容区瓦斯突变压力梯度显著增大,含瓦斯煤失稳致灾敏感性增强。构建了含瓦斯煤瓦斯压力和采动应力耦合作用力学模型,表明工作面煤层瓦斯压力受控于采动应力,且呈指数正相关性。揭示了工作面煤层瓦斯压力受控于采动应力的扩容致灾力学本质。
[Abstract]:In order to reveal the inherent mechanics mechanism of the disaster caused by gas seam expansion in deep wells, the mechanical characteristics of the expansion process of gas-bearing coal seam are systematically studied from macroscopic and meso perspectives. There are two kinds of mechanical states in the coal seam affected by mining dynamic stress, namely, the capacity of expanding slowly and the gas pressure increasing with the increase of the dynamic stress in the coal face, and the accumulative capacity of the coal bed in the area of dilatation is increasing slowly, and the gas pressure increases with the increase of the mining stress. The accumulative expansion capacity of the coal bed in the area of expansion and sudden change of capacity leads to the sudden decrease of the gas pressure in the coal bed, which is easy to induce the dynamic disaster. The capacity expansion rate of coal body is obviously increased, the gas sudden pressure gradient is obviously increased in the expansion area, and the sensitivity of gas coal instability induced by disaster is enhanced. A mechanical model of coupling effect of gas pressure and mining stress of gas bearing coal is established. The results show that the gas pressure in the coal seam is controlled by the mining stress and is exponentially positive correlation, which reveals the nature of the disaster induced by the gas pressure of the coal seam controlled by the expanding mining stress in the coal face.
【作者单位】：安徽理工大学深部煤矿采动响应与灾害防控安徽省重点实验室;淮南矿业(集团)有限责任公司;中国矿业大学(北京)资源与安全工程学院;
【基金】：国家自然科学基金资助项目(51174003,U1361208)
【分类号】：TD712

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