Fracture damage prediction in fissured red sandstone under uniaxial compression: acoustic emission b-value analysis

In this paper, uniaxial compression tests are conducted on fissured red sandstone specimens to predict fracture damage (large-scale events). The acoustic mission (AE) coupled with digital image correlation (DIC) technologies are used to monitor and record the real-time cracking process of tested specimens. The AE characteristics are analysed during the cracking process. Moreover, three types of b-value methods based on the AE parameters are adopted to predict the occurrence of large-scale events (macro-cracking). The results show that every macro-cracking leads to a rapid decrease in three types of b value. When the fissured specimens reach to ultimate failure, all three types of b value reach to the minimum. The b value based on the AE parameters can be used as a predictor of large-scale events during the cracking process of fissured rocks.