Fracture mechanical properties and identification of principal stress direction from the rock frequency domain

The characterization of rock instability precursors and the identification of principal stress direction are essential for the safety construction of underground engineering. This study explores the characterization of rock instability precursors from the frequency domain and identification of principal stress direction by the anisotropy of frequency variation. The results show that the dense distribution of peak frequency and frequency centroid in the high frequency domain, along with an increase in peak frequency bandwidth and a decrease in mean frequency centroid value, can be used as frequency domain criteria for rockburst prediction and early warning. Both peak frequency and frequency centroid are effective monitoring parameters for rock instability. The anisotropic frequency centroid variation can be used to identify the principal stress direction, and a process is proposed. This paper not only offers a valuable complement to existing methods for rock instability precursor and principal stress direction identification, but also provides a new analytical method for stability monitoring in rock engineering.