Modelling of responses and rutting profile of a flexible pavement structure in a heavy vehicle simulator test

A flexible test road structure was tested in a heavy vehicle simulator test to monitor its performance behaviour. Water was added to the structure half-way through the test. The raised water level had a significant effect, decreasing the resilient modulus and increasing the rate of accumulation of permanent deformation. Numerical analyses to simulate the pavement responses have been carried out using both a two-dimensional multi-layer elastic method as well as three-dimensional finite element analysis, with material properties based on field and laboratory testing. Little difference was found between the two methods and both methods generally agreed well with the measurements. The observed accumulation of permanent deformation manifested on the surface as rutting was modelled using two simple work hardening material models; a stress-based model and a strain-based model. The stress-based model was found to be sensitive to slight response changes and had a closer fit than the strain-dependent model.