Design Charts for Retaining Walls in Seismic Areas

Retaining walls have failed either by sliding away from the backfill or due to combined action of sliding and rocking displacements, during earthquakes. Performance based design of the retaining walls in seismic areas must account for the likely displacements, in addition to calculating the usual factors of safety against failure in bearing, sliding and overturning. A realistic model for estimating dynamic displacement has been developed, which accounts for the combined action of sliding and rocking and takes into consideration, non-linear soil stiffness in sliding, and rocking, geometrical and material damping in sliding, and rocking, and coupling effects. This model was then used to calculate the displacement for several combinations of backfill and foundation soil conditions. In this paper design charts based on seismic displacements of rigid retaining walls for ground motions of Loma-Prieta, El-Centro and North ridge have been presented for poor sandy foundations (B3-F4).