Displacement-Based Seismic Analysis of Slopes, Dams and Embankments

The seismic design of slopes, dams, or embankments is usually based on limit-equilibrium calculations, which include the seismic action by means of an equivalent static force acting on the failure mechanism. This approach is limited, especially in situations in which existing over-inclined structures or steep natural slopes have to be analyzed. An alternative approach which overcomes the limitations of the classical limit-equilibrium calculations is available with displacement-based methods. The displacement-based analysis offers the possibility of evaluating the seismic behavior in terms of displacements, in contrast to the limit-equilibrium calculations, which only provide information about the ratio between the stabilizing and destabilizing forces acting on the structure. The displacement-based approach allows the analysis of the seismic behavior and, based on the resulting deformations, the corresponding risk evaluation. In addition to that, the optimized seismic design of new geotechnical structures is possible by ensuring the compliance of the seismic behavior with given requirements. This paper presents a displacement-based procedure to be incorporated in the Swiss design codes for the seismic analysis of slopes, dams, and embankments.