Design of geosynthetic-reinforced soil structures

The working stress design methods commonly used for the design of geosynthetic reinforced soil structures are usually based on assumptions concerning the anticipated state of stress (K_o or K_a) in the soil. These methods do not allow for considerations pertaining to the effect of reinforcement stiffness on the structural behavior. This paper presents the engineering application of a strain compatibility approach (recently proposed by Juran et al., 1990) for the analysis of geosynthetic-reinforced soil structures. This approach, based on simulating the strain compatibility between the soil and reinforcement, is developed to evaluate the effect of reinforcement and on the structure properties on the mobilized tension forces in the reinforcement and on the structure stability. It yields an analytic solution which is consistent with the observations on the behavior of reinforced soil structures and the recommendations of the FHWA design guidelines. This paper outlines the results of a parametric study to evaluate the effect of reinforcement extensibility and soil dilatancy on the mobilized tension forces. The analysis shows that the working stress design methods commonly used are too restrictive to allow an appropriate simulation of the complex structure behavior. Design charts are presented to predict the tension forces in the reinforcement and the locus of failure surface for different reinforcement extensibilities and soil properties. Method predictions are compared with results of the currently used working stress design methods.