A Nonlinear One-Dimensional Wave Analysis of a Triaxial Soil Specimen
A fast triaxial shear device (FTRXD) loads cylindrical soil specimens, displacing the top of the specimen downward and axially at a controlled and very rapid rate. Load and displacement at the specimen top and load at the bottom are measured; specimens are subjected to constant confining pressures. Nonlinear, one-dimensional wave analysis of the specimen was undertaken, using finite-difference methods, to assess the effects of longitudinal inertia in the specimen and to gain insights into its behavior as stress and strain approach failure levels during rapid transient loading. For conditions where radial inertia and radial shear stress do not affect normal axial stress and strain significantly, axial load measured at the top and bottom of the specimen plotted against nominal axial strain permit deducing the specimen´s correct principal stress difference-axial strain curve.