Drained Deformation of Sand Under Cyclic Stresses Reversing Direction

A series of cyclic triaxial tests with varying amplitude was performed on samples of a sand in which they were subjected to stress reversal from compression to extension and vice versa. In the first place, the effect which the previous stress history in triaxial extension may have on the current deformation characteristics in triaxial compression, and vice versa was investigated. It was found that yielding of sand in reversing stress condition could occur independent of the previous stress history in an opposite direction, as long as the stress amplitude was made to stay within some limit. On the basis of the dircetional independency as above, together with the knowledge concerning the deformation characteristics under monotonous loads, an attempt was made of assessing how dilatancy and shear strains develop progressively during cyclic loading. This method proved to be applicable not only for stress-controlled but also for strain-controlled performance of sand.