Fractal characteristics and acoustic emission b-value of cement superfine tailings backfill with initial defect consideration

To clarify the influence mechanism of initial defects on the internal crack evolution law and damage destruction of cement superfine tailings backfill(CSTB), uniaxial compression and simultaneous acoustic emission (AE) tests were carried out on CSTB with different degrees of internal initial defects constructed by doping with different contents of doping agent(DA), and the AE b-value, amplitude fractal dimensional time series characteristics and three-dimensional distribution law of AE events of CSTBs were analyzed in this paper. The research shows that the doping of DA caused the fluctuation and jump of the CSTB b-value to be significantly enhanced, and the b-value showed two jumps in the loading process. The fractal characteristics of CSTB with different DA doping are better, and the fractal dimension D-value and b-value both show a rapid decreasing trend in the preparation process of the specimen for the occurrence of overall unstable failure. The admixture of DA increases the number of initial defects and non-homogeneity within the CSTB, making the generation of 3D localization points of AE events somewhat random. The results of the study can help to better analyze the unstable failure process of the backfill in the mine hollow area and carry out the corresponding support work.

Automated summary

This study conducted uniaxial compression and simultaneous acoustic emission (AE) tests on cement superfine tailings backfill (CSTB) with different degrees of internal initial defects. The results showed that doping with a doping agent (DA) significantly enhanced the fluctuation and jump of the CSTB b-value, with two jumps observed in the loading process. The fractal characteristics of CSTB with DA doping were improved, and both the fractal dimension and the b-value showed a rapid decreasing trend before the overall unstable failure occurred. The admixture of DA increased the number of initial defects and non-homogeneity within the CSTB, resulting in somewhat random generation of 3D localization points of AE events. These findings can help better analyze the unstable failure process of backfill in mine hollow areas and carry out appropriate support work.