Numerical modeling of geosynthetic reinforced soil retaining walls with different toe restraint conditions

This paper reports numerical modeling of the prototype geosynthetic reinforced soil (GRS) walls corresponding to four centrifuge models that have different toe restraint conditions. The development of the interface stresses and displacements at wall toe during wall construction is investigated to understand how the toe carries load in the GRS walls with a practical toe structure. The numerical results show good agreement with the data from the centrifuge modeling. For the GRS walls with a leveling pad embedded in foundation soil, the shear resistance at the facing block-leveling pad interface acts as the toe resistance to counterbalance a portion of horizontal earth load, while the leveling pad-foundation soil interface play no role in wall performance because the soil passive resistance in front of the leveling pad inhibits the development of the shear stress and displacement on this interface. For the GRS walls with an exposed leveling pad, it is the leveling pad-foundation soil interface that works for carrying the earth load because the wall is more likely to slide along this weaker interface. The contribution of the toe to load capacity depends on the shear strength of the effective toe interface that contributes to the resistance against the earth load.