Serviceability performance of piled embankments considering soil-reinforcement interface interaction

Geosynthetic reinforced and pile-supported (GRPS) embankment has been widely used to address the problem of insufficient bearing capacity in soft soil areas. A simplified method is proposed here to assess the serviceability performance of GRPS embankments where the evolution of soil arching and the development of subsoil consolidation have been synthetically considered. The main innovation is that the effect of the soil-reinforcement interface interaction is particularly focused. The proposed method is validated based on the field test results and thereafter a parametric study is performed. It shows that the soil-reinforcement interface interaction decelerates the subsoil consolidation and thus suppresses the subsoil settlement. The interface interaction roughly improves the load-transferring efficiency by imposing a lesser load on the subsoil and transferring more load on piles. Enhancing the soil-reinforcement interface interaction inhibits the development of load recovery, leading to the stress carried by the subsoil and the geogrid after maximum arching drops. The effects of the coefficient of consolidation, the pile spacing and the geogrid stiffness on the serviceability performance of the GRPS embankment are investigated when involving varied interface interactions. The beneficial effect of the interface interaction is more pronounced when a greater pile spacing and a lower geogrid stiffness are involved.