Seismic response of multi-tiered reinforced soil retaining walls

• A validated Finite Element procedure was used to analyze the earthquake responses of multi-tiered reinforced soil walls.
• The resonant frequency of reinforced soil walls increased to certain extent with an increase in the tier-offset.
• Multi-tiered configuration reduced the residual lateral facing displacement and the average reinforcement load.
• The earthquake-induced reinforcement load distribution did not follow the same trend for single- and multi-tiered walls.
• Factors contributing to the improvement of seismic performance were identified.

In this study, a validated Finite Element procedure was used to investigate the similarities and differences of seismic performances between single- and multi-tiered reinforced soil walls. Three-tiered walls at a total height of 9 m were analyzed together with vertical walls at the same height. It was found from the Finite Element analyses that the resonant frequency of reinforced soil walls might increase with an increase in the tier-offset. The multi-tiered configuration could considerably reduce the residual lateral facing displacement and the average reinforcement load, and the reinforcement load distribution with height was different from that in vertical walls. With the same reinforcement length and spacing, the multi-tiered walls resulted in smaller reinforcement connection loads with the facing blocks. The study filled the gap of seismic behavior of multi-tiered reinforced soil retaining walls and revealed a few unique dynamic properties of this type of earth structures.