Abstract: A discontinuum and continuum coupling numerical model was built based on centrifuge modeling of a reinforced soil wall with rigid/flexible facings on soft soil. In the numerical model, the particle flow code (PFC) and the fast Lagrangian analysis code (FLAC) were used to simulate wall backfill and soft foundation, respectively. The deformation of the wall, the distribution of reinforcement loads along the wall height, and the internal failure evolution in the wall were simulated and analyzed. The internal failure evolution of the wall on rigid foundation was also simulated to compare with that of the wall on soft foundation. It was found that the numerical results are in good agreement with those measured in centrifuge modeling. The potential internal slip surface of the wall on the soft foundation passes through the end of the embedded anchors, and the tension in each reinforcement layer is the maximum at the end of the embedded anchors. The reinforcements in the walls are on either soft or rigid foundation break at the end of the anchors from the bottom to the top in their limit states. The walls on soft foundation fail in a plane slip passing through the end of the anchors intersecting the circular plane slip in soft foundation. However, the walls on rigid foundation slide horizontally along the bottom anchors with a plane slip at the end of the anchors.

Key words: reinforced soil walls, rigid/flexible facings, internal failure mechanism, coupling discontinuum-continuum simulation, centrifuge modeling