Date of Graduation
Statler College of Engineering and Mineral Resources
Civil and Environmental Engineering
Samir N. Shoukry.
The objective of this study was to develop Three Dimensional Finite Element Models (3D-FEM) that can be used to investigate the separate or combined effect of moving axle loads and thermal gradient on the response of dowel Jointed Portland Cement Concrete Pavement (JPCCP) structures. The availability of a mechanistic tool that can be used for an accurate prediction of rigid pavement response to such loads would enable designing longer lasting pavements and understanding some of its modes of distress. In this respect, finite element modeling offers a powerful tool for the simulation of the structural behavior of pavements under the effect of combined moving axle loads and thermal gradient. The literature review shows that many pavement computer response models based on the FE method were developed for the analysis of jointed pavement slabs, however, important considerations were overlooked. In this study, a 3D-FEM is developed to provide a comprehensive view of the dynamic response of a JPCCP section subjected to moving tire loads. The developed model overcomes the shortcomings of previous studies. The accuracy of the results obtained from this model is verified by a comparison with field measurements. A parametric study is performed to investigate the effect of several variables on the response of the concrete slab and the underlying layers. The variables studied include the effect of model, material, and design parameters on the predicted response, as well as the effect of nonlinear thermal gradient on JPCCP subjected to moving loads. The results indicate that the peak stresses developed in rigid pavement slabs result from combined positive thermal gradient and tandem or tridem axle loads and are located at the middle of the slab. Results also show that the combined negative gradient and axle loads located at the transverse joint subject the mid-slab top to high tensile stress that may explain the initiation of top-down cracks. These stresses increase under corner loading and when the slab length is increased. In general, the results show that the developed 3D-FEM is suitable for identifying the effect of different design features on the structural response of rigid pavements.
Fahmy, Michel Ramsis, "Finite element modeling of dowel -jointed plain concrete pavement response to thermal and moving traffic loads" (2000). Graduate Theses, Dissertations, and Problem Reports. 2379.