Numerical Modeling of Geosynthetic Reinforced Flexible Pavements: Fid-Bau Portal

Numerical Modeling of Geosynthetic Reinforced Flexible Pavements

S. W. Perkins

Experimental studies conducted over the course of the past 20 years have demonstrated both general and specific benefits of using geosynthetics as reinforcement materials in flexible pavements. Existing design solutions are largely empirically based and appear to be unable to account for many of the variables that influence the benefit derived from the reinforcement. Advanced numerical modeling techniques present an opportunity for providing insight into the mechanics of these systems and can assist with the formulation of simplified numerical methods that incorporate essential features needed to predict the behavior of these systems. A bounding surface plasticity model was used for the base aggregate and subgrade layers. The model is well suited for the prediction of accumulated permanent strains under repeated loading and is most suitable for fine-grained materials. A material model containing components of elasticity, plasticity, creep and direction dependency was formulated for the geosynthetic and calibrated against a series of in air-tension tests. A Coulomb friction model was used to describe sheer interaction between the base aggregate and the geosynthetic. The model is essentially an elastic-perfectly plastic model, allowing for specification of the shear interface stiffness and ultimate strength. This model was calibrated from a series of pull out tests.