(1. Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mine,University of Science and Technology Beijing,Beijing 100083,China;2. Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)
Abstract:Based on the particle flow theory and particle flow code(PFC),the simulative approach of rock acoustic emission(AE) in meso-scale is established by using the moment tensor theory. This approach can simultaneously give the occurrence characteristics of AE event such as time,location and magnitude,reproduce the generation,propagation and coalescence progress of cracks,and consequently reveal the rock failure mechanism. The reliability of this approach is verified by comparing the experiment and calculation data based upon the AE characteristics test of lab granite complete failure process. Some main research results are as follows:(1) Before the peak strength,the number and magnitude of AE events are less and lower,respectively;and they are distributed randomly in the sample. From the peak strength to failure residual strength,the number and magnitude of AE events are much more and higher,respectively;and they are distributed principally along the macro fracture belt. (2) The number of AE events behaves as normal distribution with the magnitude variation. Between the mean and peak value of magnitude,the cumulative number of AE events behaves as linear log function relationship with decrease of magnitude. (3) The number of microcrack in each single AE event increases and approximatively behaves as Boltzman function relationship with increase of magnitude. (4) The number of AE events behaves as negative exponential function relationship with the number of microcrack,namely in case the kind of AE event owns less microcracks;its proportion is higher in total AE events. The research results make up the deficiencies of the existing AE test and simulation method,and can be utilized as a new approach in the research of AE test and field microseismic monitoring.