Limit Equilibrium Analysis of Geosynthetic-Reinforced Retaining Walls Subjected to Footing Loading

Geosynthetic-reinforced retaining (GRR) walls have been utilized as bridge abutments to support shallow foundations of bridges instead of traditional deep foundations, such as piles. In this technology, GRR walls support both bridge beams on spread footings constructed directly on the reinforced soil mass and approaching roadway embankments. However, limited studies have been carried out to investigate potential slip surfaces and their corresponding factors of safety when the wall is subjected to footing loads. The focus of this study is to investigate the effect of the footing loading on global stability of GRR walls with modular block facing. The limit equilibrium (i.e., the Bishop simplified method) in the ReSSA program was used to determine the potential slip surfaces and their corresponding factors of safety. Parametric studies were carried out by varying two parameters, i.e., the width and the offset distance of the footing from the wall facing, to investigate their effects on the potential slip surface and the factor of safety. The results show that the slip surfaces began from the far edge of the footing and developed into the reinforced zone towards the wall facing. When the width of the footing was increased, under the same applied load, the factor of safety slightly increased. However, the offset distance of the footing from the wall facing had a minor effect on the factor of safety.