It is generaly believed that addition of clay or introduction of plasticity to the silt increases the resistance of silts
against liquefaction (Puri 1984). It was demonstrated by Sandoval (1989), and Prakash and Sandoval (1992),
that for plasticity index (PI) in the range of 2-4%, the liquefaction resistance of silt decreases with increasing
plasticity. In this paper it is shown that an increase of plasticity in silts does not necessarily mean increased
resistance to liquefaction both in undisturbed and remolded state. Also, other relevant data from literature which
substantiates the above hypothesis has been critically examined. There appears to be a critical PI value at which
the liquefaction resistance is minimal. Specific values for critical PI are not known at present (2000).