Experimental Study on the Effect of Bedding Dip Angle on Acoustic Signal Propagation in Magnetite Ore

Acoustic wave detection is a core non−destructive testing technique for identifying hidden disaster−inducing factors in mining engineering. However, the presence of bedding planes in rock masses can significantly alter the propagation characteristics of acoustic waves, thereby affecting or even interfering with the accurate interpretation of these hidden hazards. In this study, layered magnetite ore was taken as the research object. A combined approach of laboratory acoustic testing and numerical simulation was adopted to acquire the wave velocity, amplitude, energy, dominant frequency, and time−frequency characteristics of acoustic signals under different bedding dip angles. Simultaneously, the spatial evolution of the internal acoustic wavefield within the rock mass under various bedding dip angles was simulated and analyzed. The results show that bedding dip angle exerts a significant anisotropic control over wave velocity, wavefield evolution, and energy attenuation of acoustic waves in rocks. Specifically, wave velocity exhibits a linear negative correlation with bedding dip angle, while the attenuation coefficients of energy, vibration duration, and amplitude all increase quadratically with increasing dip angle. After traversing the bedding interfaces, the dominant frequency decreases to varying degrees, and the extent of this reduction declines linearly as the dip angle increases. Moreover, the high−energy frequency components tend to shift toward the medium−to−low frequency band and become progressively concentrated in the range of 62.5~187.5 kHz. These findings establish quantitative relationships between bedding dip angle and acoustic propagation characteristics, providing significant practical value for improving the accuracy of acoustic detection of hidden hazards in layered rock masses within mines.