Abstract
AE amplitude frequency distribution shows a power law by AE activities in the fracture process of rocks. This law is critical for the prediction of the rock fracture. Thefefbre, in the rock fracture brocess, if the relationship between the slope of AE amplitude frequency distribution and crack growth was made clear, then the prediction of rock fracture can be made possible by the analysis of the real time of AE amplitude frequency distribution.
In this study, we investigats the slope (|b| value) of the AE amplitude frequency distribution in the compaction fracture process of rock specimen and the observation of the crack growth in rock specimen after test with the microscope.
In the result of the AE measurement, the |b| value for granite and sandstone decreases before the failure, but that for marble and tuff hardly decreases. Therefore, the observation of the cracks with the microscope, for granite and sandstone revealing that the |b| value decreases, the large under ihtercrystalline cracks grow. For marble revealing that |b| value hardly decreases, the intracrystalline cracks grow closely, but, for tuff, the cracks hardly grows except for along the shear plane.
