Variation of Ultrasonic Wave Velocity of Marbles under Tri-axial Compression

Abstract

Ultrasonic wave velocity and stress-strain relation for three types of marbles with different grain sizes are measured under tri-axial compression. The range of axial differential stress and strain is up to 3Kb and 7% respectively. It is found that the strength of the marbles decreases as the grain size increases like the metallic polycrystals. In the plastic region, ultrasonic wave velocity of marbles decreases as the strain increases. A phenomenological model is proposed to explain qualitatively the behavior observed.