Abstract: It has been well recognized that the safety of embankments during earthquake cannot be evaluated solely by the safety factor of the pseudo-static stability. It is suggested by Newmark that the seismic stability of embankment should be assessed by using the seism-induced sliding movements or permanent deformations instead of the overall safety factor. However, the rational evaluation of sliding movements or residual deformations induced during earthquake cannot be made in a perfect manner. In this paper, a numerical procedure is proposed for evaluating the sliding movements of embankments based on the step-by-step dynamic response analysis and the pseudo-static limit-equilibrium analysis. In the proposed method, the dynamic responses of embankments to earthquake shaking are first predicted by FEM-based numerical analysis. The simplified Bishop’s procedure and modified simplified Bishop’s procedure of limit equilibrium are employed to evaluate the transient safety factors of potential sliding mass of embankment slopes respectively for circle slip surface and for smoothed non-circle slip surface. For the overloading in which the transient safety factor is lower than unity; the transient sliding movement can be assessed by double integration with respect to time. For the example case, the parametric computations and comparative studies are made to examine the effect of vertical component of ground motions, vertical seismic response of potential sliding mass, shaking-induced pore water pressure and other related factors on the sliding movement and earthquake-resistant behavior of embankments.

Key words: earth-rock dam, aseismic stability, pseudo-static stability analysis, seism-induced sliding movements, permanent deformations