Intrinsic seismic protection of cantilevered and anchored retaining structures

This paper explores the possibility of applying the principles of capacity design to the seismic protection of embedded retaining structures. The study hinges on the analysis of the plastic mechanisms that may be activated by cantilevered and anchored retaining walls during strong motion while preserving the integrity of the structural members. Through a combination of numerical analyses and simple limit equilibrium calculations, it is shown that that for the wall schemes considered in this work it is possible to derive the maximum internal forces that the structural members may undergo during a severe earthquake from the analysis of the relevant plastic mechanism. It is also shown that these internal forces do not depend on the amplitudes of seismic motion, but are related only to the strength of the dissipating elements of the system. For anchored walls, this approach indicates that the optimal way to limit the internal forces in the retaining wall is to design weak anchors, that during the seismic event may mobilise the strength at the contact of the soil with their injected active portion.