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Abstract The homemade integrated testing system of ultrasonic wave and acoustic emission was used in the uniaxial and the cyclic loading tests on salt rock to investigate its characteristics of deformation，ultrasonic wave velocity and acoustic emission. At the initial stage of the loading tests，the velocity of ultrasonic wave of salt rock increases significantly with the reduction of crack volume，and about 0.04% of total acoustic emission(AE) events occurred. When the salt rock enters the stage of elastic compression，the volumetric strain of rock samples increases，while the crack volume remains constant；P-wave and S-wave remains stable，and the acoustic emission activity is weak with about 2.49% of all the total AE events. When the salt rock enters the phase of linear crack growth，the shear wave velocity slowly declines and the AE events become active with about 17.3% of the total acoustic emission events. The AE events increases to 76.5% of the total acoustic emission events at the phase of accelerated crack growth，with the feature of earthquake swarm. The velocities of P-wave and S-wave begin to reduce significantly. After the peak stress，salt rock produces a small number of acoustic emission events，and the velocity of ultrasonic wave declines to the lowest level. In the test of cyclic stress loading，the ultrasonic velocity and the AE activity of salt rock varies consistently with the stress condition. The velocity of ultrasonic wave increases and the AE occurs intensely in the loading process，while the velocity of ultrasonic wave decreases and the AE occurs rarely in the unloading process. Felicity effect is confirmed and the accumulated damage is obtained by comparing the change of Felicity ratio with the results of statistical calculation of AE events and stress states.
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Received: 12 May 2014
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2014, Vol. 33 
