THE EXPERIMENTAL STUDY OF ACOUSTIC EMISSION DURING CREEP OF ROCKS

Under normal temperature, uniaxial compression, creep experiments with whole samples of Gabbro and Marble rocks are made. According to the data obtained by tests, AE activities during three stage of creeping process are discussed. At the stage of instantaneous creep, AE events increase slowly with loading for samples; at the steady creeping stage, large AE signals appear probably on a lower background of AE action; the m-value which discribes the relationship between AE amplitude and frequency remains stable and at a low value or decreases. At the accelerated creeping stage, AE activities increase and the m-value decreases quickly or decreases again after recovery. These experimental results are related to the quality of rock samples.The AE activities during the three stages of creeping and fracture process are compared with the seismic patterns (for example ?value, foreshocks) during the seismogeny of a strong earthquake. Finally, it is pointed out that possibly the mechanism of creep fracture of crus-tal rocks forms the foreshock-mainshock-aftershock earthquake sequence.