Three-dimensional reinforced slopes: Evaluation of required reinforcement strength and embedment length using limit analysis

Virtually all analyses of reinforced earth structures are based on two-dimensional (2D) conditions, ignoring three-dimensional (3D) effects despite adhering to three-dimensional behavior in reality. In this study, the three-dimensional effects of three-dimensional conditions on reinforced earth structure stability are considered, and employed to determine the required strength and length of reinforcement using a Limit Analysis approach. The results of the three-dimensional stability analysis are compared with idealized two-dimensional results and examples from prior literature. As expected, use of two-dimensional stability analyses for reinforced soil slopes yield results that are more conservative than those considering three-dimensional effects. The effects of various parameters on the three-dimensional solution are investigated and design charts are proposed. The solutions demonstrate that for practical scenarios, three-dimensional effects may affect the required length of reinforcement more than the associated required tensile strength.