Based on the increasing mode of pore pressure and the liquefaction mechanism of saturated loess
a model to analyze the dynamic stability of infinite slopes of saturated loess is established. By the model
the failures of this kind of slopes are classified into two modes: one due to liquefaction and another due to sliding. The analytical results indicate that the yield seismic coefficient
which decreases with time
is strongly affected by some soil parameters
i.e. the effective cohesion and initial pore pressure ratio. In addition
it is validated that the value of permanent displacement computed by the model
in which the pore pressure build-up is considered
is greater than by the conventional Newmark method.