Effect of surface tangential contact stresses on flexible pavement response

The objective of this study was to investigate the responses of flexible pavement to continuously moving vehicular loading under various tire configurations. Measured vertical and surface tangential contact stresses (longitudinal and horizontal) were incorporated into a three-dimensional (3D), finite element (FE) model. Results from the developed 3D FE model were successfully verified against field measurements. The predicted peak strains were comparable to the field-measured values. The study found that pavement responses at the surface and shallow interface were clearly affected by surface tangential stresses. In addition, the study found that surface tensile strains vary notably between the tire's rib and groove. When horizontal, surface tangential stresses are incorporated, there is increased potential for the development of surface-initiated, top-down cracking in the pavement surface close to a tire's edge. Because horizontal tangential stress can be as high as about 52% of the compressive vertical stress, it must be included in flexible pavement analysis. This will result in improving the prediction of pavement responses to vehicular loading, especially at shallow depth.