The reversal of the trend of A with respect to the type of
soil shown in Figs. 17 and 18, when 'Ye decreases from moderate
to very small, is similar to the reversal of the trend of A
caused by the increased silt content in sands presented in Figs.
II(a) and II(b). Such trend reversals can be explained by the
combined effect of the viscous creep (or relaxation) and soil
nonlinearity on the area of cyclic loops, aW, of different types
of soils at different levels of 'Ye.