Effects of Consolidation History on Critical State of Sand

A series of drained biaxial compression tests were conducted on two sands to determine the effects of consolidation history on their critical states. Specimens of each sand were consolidated along at least two separate paths in void ratio-effective stress space, creating several unique consolidation histories. Because the sands were dilative, strains localized during shearing and the evolution to critical state occurred only within the shear band. Digital images were obtained through a plexiglass sidewall throughout each test. Digital image correlation techniques were used to quantify the displacements within the band, and a linear regression technique was used to formulate a displacement function from which strains were computed. The critical state was achieved within the shear band in each test, but the critical state line was found to depend on the initial state and subsequent consolidation history of the sand specimens.