Numerical integration approach to the problem of simulating damage in an asphalt pavement

A road develops permanent deformation or fatigue damage because of the stress and strain induced in its structure by surface loading and environmental change. Dynamic tyre forces generated by the vibration of moving heavy vehicles excited by the road surface profile are strongly influenced by vehicle speed and dynamic properties. A mechanistic-empirical approach is implemented here to simulate the deterioration of a pavement, taking account of dynamic excitation of the axles. This paper highlights the importance of statistical spatial repeatability in damage evolution during the pavement life. Numerical integration of the distribution of forces at each point is shown to be sufficient to predict the changing road surface and elastic modulus. This results in an approximate 100-fold increase in computational efficiency. Finally, the pattern of the forces generated by the axles of a half car is found to be a little less damaging than that of independent quarter cars. In the examples considered, the quarter car reduces calculated pavement life by an average of 6%.