Abstract: An experiment is carried out to simulate granites rock burst under natural and saturated state with biaxial rigid servo-controlled system.The PCI-2 acoustic emission system produced by American Physical Acoustics Corporation is used to collect data of the acoustic emission synchronously.Then，the influence of water on tunnel rock burst is studied.It is found that the granite samples with different moisture contents show different acoustic emission characteristics in the process of rock burst.The saturated granites eject rock debris later than the natural granites.The acoustic emission of natural and saturated granites comes into quiet period when the axial load reaches 65%~80% of the peak load and the quiet period with natural granites is longer than that with saturated granites.The average acoustic emission events rate of saturated granites is higher and the duration of high acoustic emission events rate is longer than that with natural granites.The high acoustic emission energy rate of natural granites appears after that of saturated granites.The acoustic emission events rate and energy rate present trading off and taking turns in the process of granite rock burst.The initial damage of natural granites occurs after that of saturated granites.

Key words: Different moisture state, Rock burst, Acoustic emission, Damage mechanics