Influence of toe condition on mechanical response of rigid-faced GRS walls

The present design guidelines for rigid-faced (RF) geosynthetic reinforced soil (GRS) walls recommend a minimum toe embedment depth as a geometric requirement. The toe condition effect is ignored in these designs. Development of tools for serviceability design and refinement of present design methods require a complete understanding of the toe condition's role. Finite element analysis of RF-GRS walls is carried out in this study for different toe conditions, such as fixed, rotating and frictional toe, representing different construction methods. The analysis of fixed toe conditions shows 3–5 times lesser deformations and 10–20 times lesser loads in bottom reinforcements compared to other toe conditions. Reduced reinforcement stiffness at the bottom of the wall for a fixed toe condition has a negligible effect on deformations. The fascia experiences high bending moments at the bottom of the wall with fixed toe conditions. Frictional toe condition mobilizes both sliding and rotation modes of wall deformations. It also shows toe force increasing by 5–20% for embedment depth increase by 6 times. The results for rotating toe with restrained sliding show higher top displacements than other toe conditions. The use of stiffer reinforcements at the wall top reduces such rotations. Possible design concepts to impart toe fixity in the field are also discussed.