有效应力对煤样变形和渗透性的影响研究

发布时间：2018-05-04 19:40

本文选题：采矿工程 + 渗透率　；参考：《岩石力学与工程学报》2017年09期

【摘要】：为了研究渗透率随有效应力的变化特征,利用含瓦斯煤热流固耦合三轴伺服渗流装置,在外部应力不变、降低进口气体压力,外部应力、进气口压力同步降低2种实验条件下,观测了赵各庄煤矿9号煤层样品的应变和气相(氦气)渗透率,研究有效应力对煤样变形和渗透性的影响。实验结果显示,随着有效应力升高,煤样的收缩应变加剧,有效应力为5.2~6.5 MPa,收缩体积应变与有效应力之间符合线性关系,有效应力大于6.5 MPa或小于5.2 MPa,应力应变曲线发生偏折,部分煤样出现扩容现象;气体渗流速度随进口气体压力的降低而降低;升高或降低有效应力,煤样渗透率均随着进口气体压力的降低而增大。由此可见研究有效应力变化条件下的渗透率变化特征,应适当考虑气体滑脱效应的影响。
[Abstract]:In order to study the variation characteristics of permeability with effective stress, a three-axis servo percolation device with gas-bearing coal hot flow and solid coupling is used to reduce the inlet gas pressure and external stress by keeping the external stress constant. Under two experimental conditions, the strain and gas phase (helium) permeability of coal seam No. 9 in Zhaogezhuang Coal Mine were observed, and the effect of effective stress on the deformation and permeability of coal sample was studied. The experimental results show that with the increase of effective stress, the shrinkage strain of coal sample intensifies, and the effective stress is 5.2 ~ 6. 5 MPa. The relationship between shrinkage volume strain and effective stress is linear. When the effective stress is greater than 6.5 MPa or less than 5.2 MPA, the stress-strain curve is deflected, some coal samples are expanded, the gas percolation velocity decreases with the decrease of inlet gas pressure, and the effective stress increases or decreases. The permeability of coal samples increases with the decrease of inlet gas pressure. It can be seen that the influence of gas slip effect should be taken into account in the study of permeability change under the condition of effective stress change.
【作者单位】：中国矿业大学(北京)力学与建筑工程学院;重庆大学煤矿灾害动力学与控制国家重点实验室;
【基金】：国家重点研发计划(2016YFC0801401) 重庆大学煤矿灾害动力学与控制国家重点实验室访问学者基金项目(2011DA105287 FW201508) 中央高校基本科研业务费专项资金(2010QL02)~~
【分类号】：TD712

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