The relation between the variation of AE hypocenters and the Kaiser effect of Shirahama sandstone

The Kaiser effect of Shirahama sandstone was investigated using the three-dimensional source locations of the acoustic emissions (AEs) detected during two kinds of uniaxial cyclic loading in elastic stage. In the experiments AEs were detected using eight transducers in order to elucidate the relation between the migration of the AEs’ sources in the rock and the appearance of the Kaiser effect. Based on the data relative to the AE source location, the Kaiser effect can be interpreted as follows: newly formed microcracks grow to an equiblibrium configuration (e.g. some characteristic length) corresponding to the previously applied stress and this stress would be memorized in the rock through microcrack…