Shored Mechanically Stabilized Earth (SMSE) Wall Systems Design Guidelines

Federal Highway Administration2006PDFTech ReportMorrison, Kimberly FinkeHarrison, Francis E.Collin, James G.Dodds, Andrew M.Arndt, BenUnited States. Federal Highway Administration. Central Federal Lands Highway DivisionGolder AssociatesYeh and AssociatesThe Collin Group, Ltd.Anderson, Scott A.Adams, MichaelBarrows, Richard J.Alzamora, DanielSurdahl, R.United States. Federal Highway Administration. Central Federal Lands Highway DivisionUnited StatesMechanically stabilized earthRetaining wallsEarth wallsReinforcement (Engineering)GuidelinesRoad constructionDesignMechanically Stabilized Earth (MSE) WallsShoring WallsRetaining WallsHighway ConstructionHighway WideningFHWA-CFL/TD-06-001DTFH68-02-R-00001Anderson, Scott A.Contracting Officer\u2019s Technical Representative (COTR): Scott A. Anderson, Ph.D., P.E., FHWA-FLH; Advisory Panel Members: Mike Adams, FHWA-TFHRC; Rich Barrows, FHWA-WFLHD; and Daniel Alzamora and Roger Surdahl, FHWA-CFLHD. This project was funded under the FHWA Federal Lands Highway Coordinated Technology Implementation Program (CTIP).Final ReportAs a Federal Highway Administration design reference for highway projects, this report was prepared to enable the engineer to identify and evaluate potential applications of shored mechanically stabilized earth (SMSE) walls. Included in this design guideline are a literature review on similar construction and the results and interpretation of field-scale testing, centrifuge modeling, and numerical modeling of an SMSE wall system. Results of the centrifuge modeling and field-scale testing show that reduction of the reinforcement length to as little as 25 percent of the wall height (0.25H) provides sufficient wall stability, even under a considerably high degree of surcharge loading. Using the results of the modeling and field testing research, this design guideline recommends a minimum reinforcement length equivalent to as little as 30 percent of the wall height (0.3H) for the MSE wall component, provided that the MSE reinforcement length is greater than 1.5 m. The benefit of attaching reinforcement to the shoring wall is found to be small and is generally not recommended except by way of the upper two layers of reinforcement. If possible, these layers of reinforcement should overlap the shoring wall and have a total length of 0.6H. If this is not possible, then these layers should be attached to the shoring wall. Internal design requirements of the MSE wall component for an SMSE wall system differ from that of a traditional MSE wall. Equations presented in this design guideline have been developed specifically to address these requirements. The benefits of increased retaining abilities provided by the shoring wall, such as reduction in lateral load acting on the MSE wall component and contribution to global stability, are considered in the design process.95