Centrifuge modelling of retaining walls embedded in saturated sand under seismic actions

A number of cases are reported in the literature of damage or failure of gravity and embedded retaining walls during earthquakes, most of which have occurred in saturated soils (Iai and Kameoka 1993; Kamon et al. 1996; Fang et al. 2003; Koseki et al. 2012). As an example, Madabhushi and Zeng (2007) reported the structural yielding of a cantilevered quay wall during the Bhuj earthquake of 2001, where significant ground settlements occurred in the backfill concurrently with a large outward movements of the wall. As observed by Zeng and Steedman (1993), failure of retaining and quay walls during earthquakes, with associated damage to structures founded on the backfill, is caused either by a local failure in the structural members or by large displacements of the ground exceeding the serviceability conditions. It follows that two aspects are of major concern when dealing with the dynamic behaviour of retaining walls, i.e., (i) the increase of internal forces in the wall due to the inertia forces acting into the soil, and (ii) the possible occurrence of permanent displacements due to full mobilisation of the soil resistance.