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

ABSTRACT

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.

KEYWORDS:

• Initial defect
• cement superfine tailings backfill
• acoustic emission
• acoustic emission b-value
• fractal dimension

Acknowledgments

The study has been supported by the National Natural Science Foundation of China (51764013), Training Plan for Academic and Technical Leaders of Major Disciplines of Jiangxi Province (20204BCJ22005), Natural Science Foundation for Distinguished Young Scholars of Jiangxi Province (20192ACBL21014) and National Key R&D Program of China (Grant nos. 2019YFC1806001, 2018YFC1800202).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [51764013]; Training Plan for Academic and Technical Leaders of Major Disciplines of Jiangxi Province [20204BCJ22005]; Natural Science Foundation for Distinguished Young Scholars of Jiangxi Province [20192ACBL21014]; National Key R&D Program of China [2019YFC1806001, 2018YFC1800202]