Deformation of Reinforced Soil Wall-Embankment System on Soft Clay Foundation

This paper focuses on the patterns of deformation of the wall and the soft clay foundation beneath the reinforced soil mass based from the results of full-scale field tests and finite element analyses. The performances of two reinforced soil test wall-embankment systems constructed on soft clay foundation with different reinforcement types but have the same backfill soils were used in the investigation. One test facility used steel grid reinforcements (higher stiffness or rigidity) and the other used polymer grid reinforcements (lower stiffness). Measurements from the instrumentations of these test facilities were compared with the results from numerical simulations based on a finite element solution in which reasonable agreement were obtained. Parametric studies were then carried out to examine the effects of the stiffness of the reinforced soil system and the foundation on the overall deformation characteristics of reinforced soil wall. Results indicated that increasing the stiffness or rigidity of the reinforced soil system led to lower lateral spreading of the soft clay foundation owing to more lateral confinement of the underlying soil as compared with less stiff reinforced soil system. However, increasing the system stiffness had the tendency to settle more below the toe because a more stiff reinforced soil system tended to rotate more about the toe compared to that which has lesser system stiffness. Consequently, the pattern of foundation movements associated with system stiffness affected also the outward facing movement of the reinforced soil wall. It was found that the increase in reinforced soil system stiffness does not necessarily result to the reduction of the outward lateral wall deformation.