Strength and deformation behavior of sediment from the Lesser Antilles forearc accretionary prism

Abstract

The shape and morphology of the northern Barbados Ridge complex is largely controlled by the sediment yield and failure behavior in response to high lateral loads imposed by convergence. The sediment yield and failure behavior is described for any stress path by a generalized constitutive model. A yield locus delineates the onset of plastic deformation, as defined from the isotropic and anisotropic consolidation responses of high-quality 38mm triaxial specimens; a failure envelope was obtained by shearing the same specimens in both triaxial compression and extension. The yield locus is shown to be rotated into extension space and is centered about a K-line greater than unity, suggesting that the in-situ major principal stress has rotated into the horizontal plane, and that the sediment wedge is being subjected to extensional effective stress paths. -from Authors