Recent Results of French Research on Reinforced Earth

The fundamental mechanism of reinforced earth is based on friction between earth and reinforcements. Points of maximum tension in the reinforcements separate two zones: an active zone close to the face of the structure and a resistance zone analogous to the anchoring zone in the case of a tie rod. The influence of the fine fraction of the fill on the friction between earth and reinforcements has been studied in laboratory tests on samples of sand and powdered clay mixtures. Calculation methods of traction forces in the reinforcements are presented. A comparison is made between theoretical and experimental values for reinforced earth walls with and without surcharge (full-scale experiment, two-dimensional or three-dimensional models). A method based on the elastoplasticity theory is formulated for reinforced earth foundation rafts.