Effects of concave facing profile on the internal stability of geosynthetic-reinforced soil walls

Previous research has demonstrated that concave cross-sectional geometry can enhance slope stability, reduce sediment loss, and improve mining efficiency. However, studies on the use of concave facing in geosynthetic-reinforced soil (GRS) walls are limited. This study idealizes the concave facing as a circular arc whose concavity is determined by the wall height, batter and mid-chord offset. Based on the limit equilibrium analysis, a modified top-down procedure is proposed to investigate the impact of concave facing on the internal stability of GRS walls. Using the presented method, the distribution of required tension along the reinforcement layer and necessary connection load can obtain while considering the pullout capacity at a given layout and factor of safety. Sensitivity analysis, including the mid-chord offset, wall batter, reinforcement length, vertical spacing, and facing blocks, are carried out to explore the impacts of facing profile concavity on the internal stability of GRS walls. Results show that concave facing can significantly reduce the required tension along the reinforcement, and the required connection strength is sensitive to the variation in the facing profile. Increasing the wall batter can result in a greater reduction of maximum required tension for the concave wall, but it can also increase the connection load for most reinforcements. The concavity of the facing has no effect on the optimal reinforcement length, which is found to be 0.7 times the wall height. The differences in maximum required tension for various facing concavities gradually diminish when considering the toe resistance.