Abstract: Under the condition of 400 MPa confining pressure and different temperatures （from room temperature to 850℃）, features of failure and AE temporal sequences of granite have been studied. The results show that rock strength of granite decreases gradually with rising of temperature. The sample failure mode changes from abrupt instability to gradual failure and the failure types of medium changes from brittle shear fracture into semi-brittle, semi-ductile and ductile failure. With rising of temperature, the numbers of AE events decrease quickly. Meanwhile, the level of differential stress at which AE emerges also has a little increase. Below 250℃, the cumulate number of AE before the failure correspond to the exponential increasing model while the failure approaching, and the rate of exponential increasing minimizes with rising of temperature; there is no AE events has been recorded at the high temperature （650℃ and above). There is obvious influence of temperature on b value of AE temporal sequences. The b-value is higher at low temperature than that at high temperature. It has been pointed out that the AE temporal sequences represent obvious multifractal characteristics, which mainly controlled by the temporal cluster feature of AE sequences. Distribution ranges of index Textend with rising of temperature, this means the scaling types of AE temporal sequences increase with rising of temperature, and its temporal structures become more complicated and disordered.

Key words: Acoustic Emission, Temperature, Rock strength, b-value, f (T)~ Tspectra