ABSTRACT
Construction of railway embankments on soft soils significant challenges due to low bearing capacity and excessive settlement. Granular columns with geosynthetic encasement have been widely adopted to address these challenges. However, fully encasing the granular columns remains a practical challenge in the field. This study investigates the influence of encasement depth and stiffness on the performance of granular column-reinforced embankments over deep estuarine clay deposits along the eastern coastline of Australia. An axisymmetric finite element (FE) model is developed to analyse the load-bearing behaviour and settlement response of the railway embankment under overburden pressures resulting from the self-weight of the embankment fill and equivalent dynamic train loads. These findings reveal that the partial encasement in the upper portion of the granular columns provides an adequate performance comparable to the full encasement while offering significant practical advantages and can guide practitioners to achieve the optimal configuration and cost-effective solution.
