Effects of Stress History on Deformation of Sand

The prestraining induced by prestressing, without residual lateral stresses, was found to increase the deformation resistance to incrementally applied axial load by an order of magnitude. The stress level at which a prestressed sample's load-deformation behavior changed from the stiffer, essentially elastic reloading mode to that which was predominantly plastic and resembled the normally consolidated state depended upon the magnitude of the prestress (or prestrain). The relationship between initial modulus and confining pressure for anisotropically consolidated, non-prestressed samples was found to be essentially linear. Evaluation of the changes in stress-strain response due to prestressing was also attempted using a model cone penetrometer.