Numerical Analysis of Geosynthetic-Reinforced Pile-Supported Embankments Subjected to Different Surface Loads

Geosynthetic-reinforced pile-supported (GRPS) embankments, as an economic and effective construction technique to reduce total and differential settlements, have been widely used in soft soils. Soil arching and tensioned membrane effects are two main load transfer mechanisms for this GRPS embankment system. Most studies have been done so far to investigate the GRPS embankment under uniform surface loading. However, embankments (e.g., highway and railway embankments) are often subjected to localized surface loading. In this study, two three-dimensional (3-D) finite element models were adopted to investigate the effect of different surface loads (uniform and localized) on the load transfer mechanisms in the GRPS embankments. A basic 3-D model was first established and verified against an existing laboratory test. A series of 3-D numerical analysis considering different surface loads was conducted. Simulation results showed that the GRPS embankment system performed better under uniform surface loading than under localized surface loading in terms of its deformation and load transfer. The load transferred by soil arching under localized surface loading was lower than that under uniform surface loading, while the load transferred by the tensioned membrane effect under localized surface loading was higher than that under uniform surface loading.