常规压缩下砂岩的声发射与损伤演化

Acoustic Emission and Damage Evolution of Sandstone in Conventional Compression Tests

采用MTS815.02岩石力学试验系统和AE21C声发射监测系统,研究了常规压缩下砂岩试样的声发射和损伤演化特征。试验结果表明:砂岩试样的声发射振铃计数与能量计数的变化规律相同,相关系数在95%以上;岩样应力-应变曲线中,每一次应力跌落都伴随有较大的声发射振铃计数率产生;声发射振铃计数间接反映了岩样内部微裂隙的萌生、扩展和贯通过程,采用声发射振铃计数定义的损伤变量能很好地反映岩石损伤演化过程。

The acoustic emission and damage evolution characteristics of sandstone under conventional compression were studied by MTS815.02 rock mechanics test system and AE21C acoustic emission monitoring system. Test results showed that the change rules of acoustic emission ringing count of sandstone samples were the same with those of energy counting, and the cor- relation coefficient was more than 95%. In the stress-strain curves of rock samples, each stress drop was accompanied by large acoustic emission ringing count rate. Acoustic emission ring count indirectly reflected the initiation, propagation and coalescence process of micro-cracks in rock samples. The damage variables defined by acoustic emission ring count can well reflect the evolution process of rock damage.