Experimental investigation on the acoustic emission and the b-value dynamiccharacteristics of different hard-rock failure

In order to investigate the difference of acoustic emission and b-value dynamic characteristics in different hard-rock failure process, the acoustic emission experiments of different hard-rock were carried out under uniaxial loading, and the stress-strain curves in the process of failure were obtained, and the dynamic characteristics of acoustic emission energy rate were analyzed and compared.The b-value was calculated based on the power law relation between amplitude and magnitude; the evolution characteristics of b-value during different failure processes were compared.The relational about stress level and b-value was analyzed.The results show that the yield points of rock with high strength and brittleness are not obvious, and the magnitude of the AE energy rate is bigger; the b-values of all rock samples began to decrease when they were fracture, but the decline of granites were greatest.