Three-dimensional numerical modelling of geosynthetic reinforced pile-supported embankments over soft ground

Construction of embankments over soft ground is a challenging task for geotechnical engineers. This is mainly due to the undesirable characteristics of soft soil such as low bearing capacity, insufficient shear strength and very high compressibility which can result in bearing failure, large settlements and local or global instability. Geosynthetic reinforced pile-supported (GRPS) embankment provide an effective solution to overcome these issues. With use of this technique a higher portion of the embankment load can be transferred to the piles rather than the soft foundation soil, thus reducing the stresses applied on to the soft soil. The performance of a GRPS embankment can vary with different parameters such as pile spacing, pile diameter, stiffness of the geosynthetic layer, elastic modulus of the piles and height of the embankment. This study presents the results of a parametric study using the finite element modelling to investigate the behaviour of a GRPS embankment. Three-dimensional numerical modelling is carried out considering two rows of piles to investigate both longitudinal and transverse load transfer mechanisms. The variation of maximum settlement at the crest of the embankment, tension in the geosynthetic layer and the stress concentration ratio with the earlier mentioned parameters are also discussed in the paper.