Earthquake-Induced Displacements in Sand Embankments

If an embankment of dense granular material is accelerated so that all points of the slope experience approximately the same acceleration at the same time the result of overstressing is a surface slide involving a thin layer of soil. The yield acceleration at which this slide will begin to move on any cycle of acceleration can be expressed in terms of the angle of friction ∖a/ and a shear strength intercept si, both of which are functions of the cumulative downslope displacement. Procedures for computing the magnitude of slope displacements resulting from a sequence of acceleration pulses are presented. Surface displacements determined using these procedures have been shown to be in reasonable agreement with those measured in banks of sand subjected to base acceleration, provided allowance is made for the variation in soil strength and yield acceleration with increasing displacements.