Effect of geosynthetic creep on reinforced pile-supported embankment systems

Geosynthetic-reinforced pile-supported (GRPS) embankments provide an effective solution to the problems faced by geotechnical engineers when dealing with embankment construction on soft foundation soils. Introduction of piles will reduce the embankment load transferred to the soft soil and the addition of a geosynthetic reinforcement layer will enhance the load transfer to the piles while alleviating the uneven settlements at the crest of the embankment. Numerous studies have been carried out regarding GRPS embankments throughout the last few decades including both experimental work and numerical studies. However, the creep effects of the geosynthetic layer were not investigated in these studies. This paper presents a numerical analysis carried out on a GRPS embankment based on the finite-element method including the creep effects of the geosynthetic layer. The creep model used in the analysis was validated using experimental data from previous studies which involved a geosynthetic pullout test and uniaxial tensile tests. The analysis was carried out in three-dimensional condition and the interaction between the soil and the geosynthetic layer was also taken into account. Furthermore, results from a parametric study to investigate the significance of creep on the overall behaviour of GRPS by varying the creep model parameters are presented.