Numerical modelling of centrifuge dynamic tests on embedded cantilevered retaining walls

This paper presents the results from the numerical simulation of two dynamic centrifuge tests carried out on embedded cantilevered walls in dry sand, reconstituted at two different values of relative density. Plane strain analyses were performed using an advanced constitutive model for the soil, in which the set of model parameters was calibrated on the basis of standard laboratory tests. The results show that advanced numerical modelling provides a good description of the seismic response of embedded retaining walls: very good agreement between numerical predictions and centrifuge data is obtained in terms of accelerations, while some discrepancies are observed in terms of displacements and bending moments in the walls, mainly due to experimental factors not taken into account in the numerical analyses. The dynamic behaviour of embedded cantilevered retaining walls is strongly related to the redistribution of the stress state around the excavation induced by the inertia forces into the soil. More specifically, permanent rotations of the wall induce a progressive mobilization of the soil passive resistance and a consistent increase of the internal forces into the wall. Furthermore, significant displacements can be attained during an earthquake even for maximum accelerations smaller than the limit equilibrium critical value.