Abstract:To investigate the influence of the bedding angle, β, on the mechanical properties and rockburst proneness, uniaxial compression tests were conducted using cylindrical phyllite specimens with different bedding angles. According to the results, the peak stress, peak strain, cumulative acoustic emission counts, and potential energy of the elastic strain exhibited a U-shaped change trend. With an increase in β from 0° to 90°, the failure mode transformed from tensile splitting failure along the bedding plane to shear slip failure along the weak bedding plane. Finally, the failure mode evolved into a tensile splitting failure across the bedding plane. When β=15°, 30°, and 45°, the phyllite specimens exhibited strong, slight, and moderate rockburst proneness, with strong, slight, and moderate shear slip rockbursts, respectively. When β=0°, 60°, 75°, and 90°, the phyllite specimens had extremely strong rockburst proneness, and an extremely strong strain rockburst occurred.

Key words: phyllite; bedding angle; mechanical properties; failure mode transformation; rockburst proneness