Abstract: In order to study the AE(acoustic emission) temporal and spatial evolution and distribution in the failure process of different size rocks and its influence on the AE in failure process of rock, and according to the physic-mechanical parameters of a mine rock specimen, the AE temporal and spatial characteristics of rock under six kinds of different scales with the same homogeneity and ratio of height to diameter were studied by using numerical simulation software. The test results show that the larger AE events obviously occur before and after the formation of the main fracture for a smaller rock specimen, in which AE events transited from disorder in the whole specimen to nucleation in the middle of specimen at the phase of post-peak. For a larger rock specimen, few random AE events prior to peak stress and larger AE events with remarkable counts and energy nucleate and occur only after the peak stress, which is closely related to the discreteness of defects strength in different sizes of rock samples.

Key words: Time sequence, Spatial distribution, Scale effect, AE spatial and temporal characteristics, Stress-strain-AE characteristical curve