Influence of facing vertical stiffness on reinforced soil wall design

Current design practices for reinforced soil walls typically ignore the influence of facing type and foundation compressibility on the magnitude and distribution of reinforcement loads in steel reinforced soil walls under operational conditions. In this paper, the effect of the facing vertical stiffness (due to elastomeric bearing pads placed in the horizontal joints between panels) on load capacity of steel reinforced soil walls is examined in a systematic manner using a numerical modelling approach. Numerical modelling was carried out using the commercial finite element program PLAXIS. The numerical model was verified against measurements recorded for an instrumented 6 m-high wall reinforced with steel strips. The influence of the facing stiffness and backfill-foundation stiffness combinations on the vertical load through the facing and on the magnitude and distribution of the reinforcement loads was examined. For walls subjected to operational (working stress) conditions at end of construction, the numerical results confirm that the vertical stiffness of the facing and soil-stiffness combinations can have a great effect on the vertical facing loads and on the magnitude and distribution of the load mobilized in the soil reinforcement layers.