Soil–Reinforcement Interaction: Effect of Reinforcement Spacing and Normal Stress

This paper presents, evaluates, and discusses experimental results of soil–reinforcement interaction tests conducted using a new device developed to assess the mechanical interaction between soil and reinforcement considering varying reinforcement vertical spacings. The experiments involved testing a geosynthetic-reinforced soil mass with three reinforcement layers: one was actively tensioned and the two neighboring layers were passive. Shear stresses from the actively tensioned reinforcement were conveyed to the passive reinforcement layers through the intermediate soil medium. Soil-reinforcement interaction tests were conducted with varying reinforcement vertical spacings and normal stresses. The load conveyed to the neighboring reinforcement layers was found to increase with increasing load in the actively tensioned reinforcement layer. The magnitude of load transfer was found to increase with decreasing vertical spacing, while the normal stress was determined to have a negligible effect on the magnitude of load transfer for the case of active loads representative of working stress conditions. However, since the soil–reinforcement interface strength decreases with decreasing normal stress, the magnitude of load transfer was observed to decrease with decreasing normal stresses for comparatively large active loads.