Changes of Yield Stress of Sand During Undrained Cyclic Loading

In this study, the yield locus of sand being subjected to several cycles of undrained loading was investigated by using the triaxial testing device capable of measuring the acoustic emission, AE, of soil. The AE measurement indicates that the undrained shear on isotropically consolidated sand changes the shape of yield locus so as to have more kinematic hardening type of yield locus. More importantly, a change occurred in the size of yield locus, and the undrained loading has reduced the size of yield locus. Subsequent undrained cyclic loadings further reduced the size of yield locus so that there were some additional yielding during the cyclic loadings which accompanied gradual accumulations of pore water pressures