Triaxial experiment study of acoustic emission laws of calcareous sand
CHEN Qing-yun1, SUN Ji-zhu2, WANG Ren3 (1. Wuhan Institute of Technology, Wuhan 430073, China; 2. School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, China; 3. Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China)
Particle breakage of calcareous sand occurs at lower stress level, and it results in stronger acoustic emission (AE). Triaxial shear tests on calcareous sand at Yongshu reef of Nansha islands are carried with different confining pressure, initial pore ratio and grain gradation, at the same time AE signals from sand are monitored. Test results show when confining pressure increases or initial pore ratio decreases, deviator stress peak value increase gradually, but AE is the strongest or weakest at some confining pressure or pore ratio limit individually; if the gradation of calcareous sand is poorer, its AE is weaker at the beginning of test; and deviator stress peak value is also smaller.