Liquefaction and Fabric of Sand

Abstract

It is shown for simple shearing that the liquefaction and densification potentials of a cohesionless sample of sand do not necessarily decrease because of preliquefaction or because of large amplitude (drained) prestraining. In fact, in simple shearing, the resistance to liquefaction (undrained) or densification (drained) of a preliquefied sample actually increases, as a result of the concomitant densification, if the preliquefaction is terminated at zero residual shear strain, whereas this resistance is reduced considerably, if the preliquefaction is terminated at zero residual shear stress. The inherent anisotropy associated with dry pluviating and moist tamping sample preparation techniques is shown to affect the sample response to consolidation and to simple cyclic shearing. It is found that, within each cycle of simple shearing, the induced anisotropy is essentially wiped out in the neighborhood of the zero shear strain (but not at zero shear stress), and the anisotropy that remains at this state basically stems from the sample preparation technique. With the aid of the dilatancy‐fabric relation proposed by Nemat‐Nasser for simple shearing, the volumetric strain of the sample is estimated using a simple distribution function for illustration purposes, and the results are compared with the experimental data.