Flexible pavement dynamic response analysis and validation for various tire configurations.

摘要

Flexible pavement responses to vehicular loading such as critical stresses and strains, in each pavement layer, could be predicted by the multilayered elastic analysis. However, most of conventional approaches suffer from major drawbacks including material properties considered in the analysis, and assumptions related to tire-pavement contact area and stresses. To address these shortcomings, three-dimensional finite element models were developed and numerical analyses were conducted to calculate pavement responses to two tire configurations: a dual-tire assembly (275/80R22.5) and a wide-base tire (455/55R22.5). To overcome the drawbacks in conventional pavement analyses, more advanced conditions such as the viscoelastic material characterization of HMA, the moving wheel load amplitude, surface tangential contact stresses, and frictional layer interface conditions were successfully incorporated into the developed 3D FE model in this study. The outcome of this study shows that flexible pavement responses are dependent on the analysis methods (e.g. quasi-static vs. implicit-dynamic), as well as the time-dependent history of the hot-mix asphalt (HMA). Results, obtained using implicitdynamic analysis, were in agreement with field measured responses. It was evident that the continuous loading amplitude can simulate pavement responses to vehicular loading more accurately than the conventional trapezoidal amplitude. In addition, the incorporation of surface tangential loading into pavement FE analyses may significantly enhance the model prediction capabilities; especially near the pavement surface. Finally, pavement damage potentials including primary rutting and top-down cracking were investigated utilizing critical pavement strain responses. The new generation of wide-base tires (455/55822.5) induces less vertical shear strain within HMA than the dual-tire assembly (275/80822.5). This will result in lower top-down cracking potential and less primary rutting. On the other hand, comparable compressive strains at top of subgrade due to both tires were obtained. This may result in comparable secondary rutting.