论文部分内容阅读
为了探究瓦斯抽采过程中煤岩动力灾害演化过程,了解煤体低温氧化对瓦斯突出影响的作用机理,通过保水法测孔隙率、P波波速测量、瓦斯放散初速度△p和煤岩坚固性系数f来评估瓦斯抽采过程中煤体低温氧化对煤岩动力灾害发生的影响。实验表明:随着煤体氧化温度的升高,煤体质量和P波波速持续降低,煤体内部裂隙逐步发育,孔隙率提高了73.3%;由于煤体内部裂隙发育,煤体结构遭到破坏,坚固性系数随着煤体氧化温度的升高而降低;与煤体坚固性系数相反,由于煤体内部裂隙发育,为瓦斯释放提供了通道,导致瓦斯放散初速度随着煤体氧化温度的升高而增加,并且升高速率逐步增加。煤体的低温氧化过程会导致煤体强度降低,瓦斯涌出压力增加,引发瓦斯突出综合预测指标K值大幅增加,煤岩动力灾害发生可能性也随着增加。
In order to explore the dynamic evolution of coal and rock during the process of gas drainage and understand the mechanism of low temperature oxidation of coal on gas outburst, porosity and P-wave velocity measurements, initial gas velocity Δp and rock solidity Coefficient f to evaluate the influence of low temperature oxidation of coal on the dynamic disasters of coal and rock during gas drainage. Experiments show that with the increase of coal oxidation temperature, the mass and P-wave velocity of coal continuously decrease, and the internal fractures of coal gradually develop and the porosity increases by 73.3%. Because of the development of coal internal fractures, the structure of coal is destroyed , And the coefficient of robustness decreases with the increase of coal oxidation temperature. Contrary to the solidity coefficient of coal, due to the development of internal fissures in coal, it provides a channel for gas release, resulting in the initial velocity of gas release increasing with the oxidation temperature of coal Increased and increased, and the rate of increase gradually increased. The low temperature oxidation of coal will lead to the decrease of the strength of coal and the increase of gas emission pressure, which will lead to a significant increase of K value of comprehensive prediction index of gas outburst and increase of the probability of coal-rock dynamic disasters.