Numerical Modeling of Wetting-Induced Settlement of Embankments

Compacted fills of embankments are typically in an unsaturated state. Water infiltration can weaken the embankments, resulting in excessive deformations and/or embankment slope failure. In this study, the Barcelona Basic Model (BBM) was implemented in the computer program FLAC (2D) to simulate the behavior of unsaturated soils. The BBM implementation in FLAC was verified using analytical results available in the literature. The verified BBM model in FLAC was then used to simulate the wetting-induced response of an example unsaturated embankment due to complete saturation as a worst-case scenario for the embankment design. It is shown that the magnitudes of wetting-induced deformations in the embankment could result in measurable amount of differential settlement in the embankment and even embankment slope failure.