Application of limit equilibrium (LE) analysis yields the critical slip surface and its associated minimum safety factor. However, at a limit state it produces little information about the local loading of an individual reinforcement including its connection load. In this presentation, the Safety Map, generated by LE analysis, is modified so as to attain a prescribed constant Fs at any location within the reinforced soil mass. Such modified framework, implemented through an iterative, top-down procedure of LE slope stability analysis, enables one to generate the Tension Map showing the distribution of reinforcement tension required to attain the same Fs everywhere. This tension map is constrained by a pullout capacity envelope at both the rear and front of each reinforcement layer, providing a robust and consistent LE-based approach towards assessing an optimal selection of reinforcement. The approach can consider complex slope geometries and layouts of reinforcement. To illustrate the utility of the Framework, a series of instructive examples are presented. The developed methodology was published in 2016 as FHWA-HIF-17-004, “Limit Equilibrium Design Framework for MSE Structures with Extensible Reinforcement” and was recognized in AASHTO 2020 as an alternative design method for geosynthetic-reinforced walls.
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