Modelling Whole-Life Flexible Pavement Performance

A new ‘whole-life’ pavement performance model (WLPPM) has been developed. It is capable of making deterministic pavement damage predictions due to realistic traffic and environmental loading. A vehicle simulation is used to generate dynamic tyre forces that are a function of distance along the road. These dynamic tyre forces are then combined with the appropriate pavement primary response influence functions (stress, strain and displacement) to give primary response histories at regularly spaced points along the pavement. The primary response histories are then transformed into increments of pavement damage (fatigue and permanent deformation) using an appropriate damage model. The result is the theoretical damage at each point along the pavement due to a single vehicle pass. The pavement surface profile is then updated to reflect permanent deformation damage, and the layer material parameters are changed to reflect fatigue damage. The procedure is then repeated for the next vehicle pass. Particular attention is given to modelling strength variations in the pavement and dynamic tyre forces.