• Water disturbance significantly amplifies acoustic emission activity, with AE hits and accumulated energy increasing by 8.77 and 12.08 times, respectively, compared to pre-disturbance levels.
• Water disturbance alters the failure mode of high-stress rock, increasing the proportion of tensile failure while reducing shear failure.
• AE events concentrate in permeation areas near boreholes, indicating that water weakening of local mineral structures promotes crack extension and overall instability.
• Saturated specimens under water only fail when the applied load approaches their saturation strength, highlighting the critical role of water saturation in rock failure.