Cumulative deformation behavior of GRS bridge abutments under cyclic traffic loading

This paper presents an experimental study on reduced scale geosynthetic reinforced soil (GRS) abutment models subjected to cyclic traffic loading, aimed at investigating the influences of cyclic load amplitude, self-weight of bridge superstructure, and reinforcement vertical spacing on the cumulative deformations. The GRS abutment models were constructed using sand backfill and geogrid reinforcement. A static load was first applied to account for the self-weight of bridge superstructure, and then the cyclic loads were applied in several phases with increasing amplitude. The results indicate that significant cumulative footing settlement under cyclic loading mainly occurs within the first few hundred loading cycles, and the settlement increases with increasing cyclic load amplitude. The cyclic load amplitude and reinforcement vertical spacing have significant impacts on the cumulative deformations of GRS abutments under cyclic loading. The maximum facing displacement under cyclic loading occurs near the top of the wall. The cyclic load has a greater impact on the reinforcement strains near the upper middle reinforcement layers, while it has a smaller impact on the lower reinforcement layers.