Research of multi-axles effects on the flexible pavement based on the viscoelastic continuum damage model

Damages caused by the multi-axles load on the pavement are more complex, due to the interaction between axles. To investigate influences of the multi-axles load on the bottom-up crack of the flexible pavement, the equivalent factor (EF) that represents damage ratios of multi-axles to single-axle based on the viscoelastic continuum damage model was proposed. Through the finite element method, influences of temperature, pavement thickness, and axle configuration on the EF were analyzed. Results suggest that the asphalt mixture with smaller m-value is more likely to have smaller EF. With the increase of temperature and asphalt layer thickness, EF of dual-axles load increases but EF of triple-axles load decreases. Besides, the wheelbase is the only factor of the axle configuration that has remarkable impacts on the EF. Making the distance between the maximum compressive and tensile stress close to the wheelbase can reduce the damage of multi-axle load.