New insights into soil arching behaviour in column-supported embankments

The observation of failure surfaces within column-supported embankments is critical to understanding how the embankment stresses are transferred towards the column heads. In this study, finite element simulations utilising a strain-softening constitutive model, nonlocal regularisation, and the Arbitrary Lagrangian–Eulerian formulation are used to examine these failure surfaces over various embankment geometries. This methodology offers insights into the nature of the failure mechanism, the development of a plane of equal settlement, and the influence of the subsoil settlement profile. Depending on the embankment geometry, the results indicate a punching failure, inverted general bearing failure, or a localised failure develops. The transition between punching and inverted general bearing failure is found to be closely related to the establishment of a plane of equal settlement within the embankment. The height of the plane of equal settlement and the range of failure mechanisms that develop were largely insensitive to the nature of the subsoil settlement profiles simulated. These findings have implications for the practical design of efficient embankments and the effective design of future experimental studies.