摘要
查明不同加卸载路径下煤岩渗透率变化特征是进行采、掘过程中煤岩裂隙变化规律研究的基础。利用RMT-150B型岩石力学伺服实验系统对不同煤样进行了不同应力、不同变形阶段的多次加-卸载下的渗透性测试试验,基于孔裂缝的演化机理对渗透性变化规律进行总结,并对变化机理进行了分析。结果表明:峰值前进行加卸载时,渗透性变化幅度较小;应变-渗透性曲线较应力-应变曲线滞后性不明显。其变化主要取决于弹性变形;峰值后进行加卸载时,渗透性发生质的变化,增加幅度较大,并且应变-渗透性曲线较应力-应变曲线滞后性明显,其变化主要取决于塑性变形。同时随着循环加卸载次数的增加,渗透性均是逐渐变大,尤其是同一加卸载过程中相同应变所对应的加载与卸载时渗透性的差值。
It is the basis to study the changing law for coal crack fissure in the process of mining and digging by finding out the laws of permeability of coal petrography under different loading and unloading paths. With RMT- 150 B rock mechanics test system,the permeability tests of conventional tri- axial and loading- unloading of different coal samples were tested in different stress and different deformation steps. The variation of permeability was summarized based on the evolution mechanism of pore fissured,and the mechanism of change was analyzed. The results showed that when loading and unloading was before the peak,permeability was changed in a lesser extent; the lag of strain- permeability curve was not obvious,compared with stress- strain curve. The variation mainly depended on the elastic deformation. When loading and unloading was after the peak,the permeability was changed absolutely,and increased by a big amplitude. At the same time,the lag of strain- permeability curve was very obvious,comparing with stress- strain curve,the variation mainly depended on the plastic deformation. At the same time,with the increases of cyclic loading and unloading times,the permeability became larger by degree. In particular,in the same process of loading and unloading,the difference of permeability between the loading and unloading in the sane strain was great.
出处
《煤矿安全》
CAS
北大核心
2015年第10期175-178,共4页
Safety in Coal Mines
关键词
加卸载路径
应力-应变
煤岩渗透率
岩石力学
循环加卸载
loading and unloading path
stress-strain
coal or rock permeability
rock mechanics
cyclic loading and unloading
