| Popis: |
The failure of rock materials in compression test suffers three characteristic stages: crack initiation, crack damage threshold, and macro-failure. There are some methods which can be adopt to identity the characteristic strengths in uniaxil or triaxial compression such as crack strain identifying method, AE activity and longitudinal wave velocity monitoring methods. In this paper, an creative experiment of recording stress-strain data, AE spectrums, and velocity of longitudinal wave is proposed and put into practice. Test results show that the mean initiation strength and damage strength by ratio of UCS are between 0.38 to 0.52 and 0.82 to 0.86 respectively with AE and longitudinal wave velocity methods synthetically. The AE monitoring method and the lateral P-wave or the axial S-wave test is an effective indicative of identifying the damage threshold when subject an axial compression failure. |
