Soil arching mechanisms in piled embankments on soft soils: Floating versus embedded piles

Abstract

Soft soil deposits are frequently encountered along large-scale transportation infrastructure such as highways and railways. These soils pose significant challenges due to their low shear strength and high compressibility, which often lead to excessive settlements, differential deformations, and, in severe cases, structural failure. The behavior and design of piled embankments constructed over soft soils are strongly governed by the soil arching effect, which involves the redistribution of stresses between the yielding subsoil and the adjacent non-yielding zones. A piled embankment supported by end-bearing piles is considered a reliable technique for improving soft ground conditions. Nevertheless, this approach is feasible only when the compressible soil layer is relatively shallow. In regions where the soft deposit extends to considerable depths, the use of end-bearing piles becomes economically impractical. In such situations, floating (friction) piles are adopted as an alternative foundation solution. The majority of existing soil arching models are formulated to account for embedded piles. Because limited knowledge exists on how floating piles affect soil arching in piled embankments, the present study investigates this phenomenon through a series of numerical FEM analyses that compare full-scale embankments built over embedded piles with those supported by floating piles.