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岩石在渗流作用下的损伤演化过程是当代岩土工程界最为关注的话题之一,为探究岩石在渗流压—应力耦合下的损伤演化特征,对取自某矿井工程的砂岩进行了三轴压缩渗流声发射试验。研究结果表明:渗透率随着应力的增加呈先减小后增大的整体趋势,在峰值应力附近达到最大值,峰后略有降低,围压越大,渗透率越小;声发射在渗透试验过程中呈阶段性变化,围压越大,声发射现象越滞后;利用weibull分布函数,基于声发射振铃计数计算得出,砂岩在渗流—应力作用下损伤量主要集中于应力加载阶段,渗透损伤仅为整体总损伤的10%~15%,且主要集中于屈服阶段之后,围压越大,渗透损伤量所占比重越小;砂岩的分形维数呈逐渐减小趋势,表明砂岩经历了一个从无序到有序的损伤演化过程,围压越大,对应的分形维数越小。
The damage evolution of rock under seepage flow is one of the most concerned topics in contemporary geotechnical engineering. In order to explore the damage evolution characteristics of rock under the coupled seepage-pressure-stress coupling, the sandstone taken from a mine is subjected to triaxial compression Percolation acoustic emission test. The results show that the permeability decreases first and then increases with the increase of stress, reaching the maximum around the peak stress and slightly decreasing after the peak. The larger the confining pressure, the smaller the permeability; The weibull distribution function, based on acoustic emission ring counting, shows that the damage amount of sandstone under seepage-stress mainly concentrates in the stress loading stage, The infiltration damage is only 10% ~ 15% of the total damage, and mainly concentrated in the yield stage, the larger the confining pressure is, the smaller the proportion of infiltration damage is. The fractal dimension of sandstone decreases gradually, indicating that sandstone experiences From a disorder to an orderly damage evolution, the larger the confining pressure, the smaller the corresponding fractal dimension.