In this study, the effect of frequency, j, on ~ was not found.
The lack of effect of j on ~ can be explained with the help of Fig. 1. This figure illustrates how the ordinates of the
stress-strain curve are typically larger for a higher rate of monotonic
straining, .y =d'Y/dt, i.e., how a larger .y yields larger
stresses, T, at any given 'Y (Whitman 1957; Mitchell 1993).
Furthermore, it has been observed that, for many soils, a fastmonotonic-
loading stress-strain curve can be obtained approximately
by multiplying the ordinates of the slow-monotonicloading
curve by a constant (Dobry and Vucetic 1987; Vucetic
and Dobry 1988). This means that the initial loading curve b
in Fig. 1 can be obtained approximately by multiplying the
ordinates of the initial loading curve a by TeblTea.