A procedure to design geosynthetic-reinforced earth-retaining walls under seismic loadings

This paper describes a new procedure for the performance-based design of geosynthetic-reinforced earth-retaining walls (GREs) using the pseudo-static approach. In this procedure, the seismic coefficient k is calibrated against given levels of seismic performance, the latter typically expressed in terms of threshold values of the permanent displacements accumulated during the seismic event. An equivalence between the seismic-induced upper-bound displacements and the seismic coefficient k is obtained applying the Newmark’s sliding-block analysis to an updated version of the Italian seismic database, correcting the computed empirical relationships to account for the shape of the internal plastic mechanisms, this involving the strength of the reinforcement levels. For a desired level of seismic performance, the wall is therefore designed to obtain the seismic coefficient related to an internal mechanisms (kintc ) lower than that associated to an external mechanism (kextc ), thus promoting the activation of plastic mechanisms which mobilise the strength of the soil reinforcement system that is assumed to be characterised by an adequate extensional ductility.