【摘要】 采用自主研发的三轴应力渗流实验系统,进行了不同应力水平循环加、卸载的力学变形及渗透率测试,研究了煤样疲劳破坏过程中煤样力学变形及渗透率对应力水平的响应特征。结果表明:应力应变曲线滞回环呈现疏-密-疏三阶段特征,随水平应力的升高,循环次数大大降低,滞回环也越稀疏;渗透率随循环次数呈现逐渐"降低—稳定—加速"升高三个阶段,整体曲线呈"U"型,并且随着应力水平的升高,曲线有向"V"型发展的趋势。煤样的力学变形与渗透性变化具有密切的关系,在循环过程中,煤样渗透率的变化趋势与应变累积量增速的变化趋势具有一致性,都经历了"减速—稳定—加速"的过程。更多还原

【Abstract】 The permeability and mechanical deformation tests were conducted with the self-developed triaxial stress seepage experiment system under different stress levels,and the characteristics of permeability variation and mechanical deformation in coal samples fatigue failure process were studied on the response of stress level. The test results show that: the hysteresis loops of the stress-strain curves shows the three stage characteristics of sparse-dense-sparse,and with the increase of horizontal stress,the cycle times are greatly reduces and the hysteresis loop is less; with the increase of cycle numbers,the permeability shows three stages of reduce-stability-rising,the whole curve presents "U"type,and with the increase of stress level,the curve has the trend of"V"type. The mechanical deformation and permeability changes have close relationship in coal samples,in the process of circulation,the change tendency of the coal samples in permeability and strain accumulation volume growth were the same,which experienced the process of decelerate-stabilize-accelerate.更多还原