Discussion of “Evaluation of Liquefaction by Energy Principles” by J. Ludwig Figueroa, Adel S. Saada, Liqun Liang, and Nitin M. Dahisaria

Abstract

SchemaUc Local Insublilly i nitl al where D. = ultimate (residual) disturbance (Fig. 12); and A and Z =parameters that can depend on (J;, p, and 6. Here, D is plotted such that D. = 1.0, where the ultimate stress approaches zero. The values of D. are related to the observed behavior when the ultimate stress (strength) approaches a value greater than zero. The values of critical disturbance, De' marked in Fig. 12, indicate points where the rate of change in D experiences a significant change (increase), and the points are identified by the stationary conditions based on the first and second derivatives of D with respect to £0 (Desai and Toth (in press, 1994). The disturbance D can be defined in terms of observed stresses, volume, or nondestructive (ultrasonic) velocities [Desai (1995) and Desai and Toth (in press, 1994)]. Here, for the cyclic behavior, a simplified form of disturbance is defined with respect to the peak values of the shear stresses (Fig. 4). Accordingly