Application of semi-analytical finite element method to analyze asphalt pavement response under heavy traffic loads

- SAFEM is able to fast and accurately predict asphalt pavement structural responses.
- The responses of asphalt pavement under heavy traffic loads are analyzed.
- The surface deflection is sensitive to the change of axle load.
- The compressive stress in asphalt binder course increases more significantly.

Accurate assessment of the impact of heavy traffic loads on asphalt pavements requires a computational model which is able to calculate the response of the pavement fast and precisely. Currently the most finite element analysis programs based on traditional methods have various limitations. A specific program SAFEM was developed based on a semi-analytical finite element method to overcome the problems. It is a three-dimensional FE program that requires only a two-dimensional mesh by incorporating the semi-analytical method using Fourier series in the third dimension. The computational accuracy and efficiency of the program was verified by analytical verification previously. The experimental verification is carried out in this paper and the results show that the SAFEM is able to predict the mechanical responses of the asphalt pavement. Using the program SAFEM, the impact of heavy traffic loads was analyzed in terms of stress and strain distribution, surface deflection and fatigue life. The results indicate that if the asphalt pavement is subjected to the heavy traffic load more, the thicknesses and stiffness of the pavement structural layers should be increased adequately in order to support the surface deflection. The compressive stress in asphalt binder course is relatively large and increases more significantly compared with that in the other asphalt layers when the axle load becomes larger. With comparison of the predicted fatigue life, the increase of the axle load will lead to the destruction of the asphalt pavement extremely easily.