Strain Compatibility Design Method for Reinforced Earth Walls

Abstract

The methods currently used for the design of reinforced earth walls with quasi‐inextensible metallic reinforcements are essentially based either upon the limit stress analysis concept or empirical relationships derived from observations on full scale structures. The development of an adequate working stress design method for these structures requires a fundamental understanding of the reinforcement effect on the load‐deformation behavior of the soil and a rational, yet relatively simple, load transfer model to simulate the soil‐reinforcement interaction. Furthermore, the response of the composite‐reinforced soil material to loading is highly dependent upon the initial state of stress and strain in the soil, and therefore the construction process and soil compaction can significantly affect the structure behavior under the expected working loads. A strain compatibility design approach which is fundamentally based on the analogy between the plane strain shear mechanism which develops along a potential failure surface in the actual structure and the response of the reinforced soil material to direct shearing is presented. The soil‐reinforcement load transfer model used in this analysis allows for the evaluation of the effect of soil dilatancy and extensibility of the reinforcement on the generated tension forces and on the probable location of the potential failure surface. In order to verify the model/design assumptions, numerical simulations of the construction process are compared with at‐failure observations on reduced scale laboratory model walls as well as with tension forces measured in reinforcements of both reduced scale model walls and full scale structures.