GRS — A New Era in Reinforced Soil Technology

This paper describes the shift of paradigm in earth retaining structures, from the Mechanically Stabilized Earth (MSE) structures to the Geosynthetic-Reinforced Soil (GRS) structures. MSE structures rely on the use of widely spaced metallic or high strength geosynthetics as tie-backs or "quasi-tiebacks" and heavy concrete blocks or panels as facing to stabilize the backfill; while the GRS structures makes use of closely spaced geosynthetic reinforcements and well compacted granular fill with minimal facing elements to create an inherently strong reinforced soil composite. GRS is superior to MSE in resisting both static and dynamic loads. Negative batter walls are an excellent illustration of the differences in design philosophies between MSE and GRS. A number of case histories of negative batter walls for a variety of applications are discussed. In addition, the paper points out deficiencies of the current guidelines for design and construction of MSE structures and addresses the future of the reinforced soil technology.