Review of Existing Design Methods of Geosynthetic Reinforced Piled Embankments (GRPE)

Construction of highway embankments over soft compressible soil or weak foundation soil results in many issues such as intolerable settlement, potential bearing failure, and global and local instability. In order to overcome these problems, many ground improvement methods are in use such as preloading with or without vertical drains, gravel compaction piles, piled embankments, etc. However, among these ground improvement techniques, Geosynthetic Reinforced Piled Embankment (GRPE) stands out due to its efficient load transfer mechanism and less construction time. In terms of design of GRPE, various researchers have introduced different methods based on different load transfer mechanisms. As such, there is an uncertainty among design engineers regarding the applicability of these design methods. This paper investigated the load transfer mechanism of GRPE using finite element analyses and currently available design methods were compared with the results of finite element modelling. Design methods were compared using output parameters of total load on a pile and geosynthetic tension by varying input parameters pile width, surcharge, soft soil stiffness, geosynthetic stiffness and embankment height. Based on the finite element analyses, the inconsistencies in the currently available design methods were identified.