Prediction of permanent deformation in the unbound aggregate and subgrade soils of a paved roadway

A finite element model of a paved roadway has been developed for the purpose of predicting the permanent surface deformation arising from the repeated application of traffic loads. A bounding surface plasticity model has been used for the unbound sub-base aggregate and subgrade soils and allows for the prediction of accumulated permanent strain under repetitive loading. The model has been formulated to match conditions present in test sections constructed in a pavement test facility. Numerical predictions from the model are compared to measured values from the test sections and are shown to approximate the development of permanent strain and permanent surface deformation with increased load cycle repetition.