Earthquake-induced permanent displacements of embedded cantilever retaining walls

Stability analysis of retaining walls in seismic areas is generally performed by calculating a safety factor against a possible mechanism of collapse. However, considering that limit conditions usually occur in some time intervals during an earthquake, a more rational approach consists in assessing the performance of the structure in terms of accumulated permanent displacements. In this context, a novel method is proposed in the present study for predicting the earthquake-induced permanent displacements of embedded cantilever retaining walls, such as diaphragm or sheet-pile walls. This method requires solving a simple motion equation of the structure subjected to the soil-structure contact stresses evaluated using a closed-form solution. Specifically, it is assumed that the wall undergoes a rigid rotation around a point located in its embedded portion. Comparisons are presented with both experimental and numerical results documented in published studies. In all cases considered, a satisfactory agreement is found between these results and those provided by the proposed method. In addition, the method accounts for some features of the seismic behaviour of embedded cantilever retaining structures observed during centrifuge tests. Summarising, the method is reliable, simple to use and requires few conventional parameters as input data. Therefore, it is suitable for routine applications.