Dynamic Response Analysis Of Asphalt Pavement Under Moving Load And Coordinated Design Of Subgrade And Pavement

The uniform distributed static load is adopted to analyze the mechanics response of pavement in the Specifications for Design of Highway Asphalt Pavement. However, the actual vehicle load is moving, besides, the actual rough road will lead to the load be inconstant. It will have some impact on the mechanics analysis and thickness design of the pavement. Based on the 1/4 vehicle suspension model with two degrees of freedom,adopting the roughness of pavement as excitation of vehicle vibration to derive theoretical solution of additional dynamic load on the rough road. The finite-infinite element model was established by using ABAQUS to calculate the dynamic mechanical response of rough pavement under moving load. Further, different typical thickness combinations of asphalt pavement with semi-rigid and flexible base were established. Adopting the results of dynamic response, based on the performance prediction models of pavement (the fatigue durability of asphalt surface, the fatigue durability of semi-rigid base and permanent deformation of subgrade), the coordination of performance index of pavement with different thickness was analyzed for different traffic levels.(1) Based on general purposed finite element software ABAQUS and applying infinite element theory, the infinite-finite element model of elastic semi-infinite foundation was established to eliminate the influence of boundary on results. The reliability of the finite element model was verified by the comparison between the finite element model and the theoretical model.(2) Based on the 1/4 vehicle suspension model with two degrees of freedom,assuming that the roughness of road is accordant with the sine waveform, adopting the roughness of pavement as excitation of vehicle vibration to derive theoretical solution of additional dynamic load on the rough road by theoretical analysis. Furthermore, the finite-infinite element model of pavement under the moving load was established to analyze mechanical response of pavement.(3) Considering different typical thickness combinations of asphalt pavement with semi-rigid and flexible base, applying dynamic response of numerical simulation, based on the performance prediction models of pavement (the fatigue durability of asphalt surface,the fatigue durability of semi-rigid base and permanent deformation of subgrade), the coordination of performance index of different thickness pavement was analyzed for different traffic levels. Furthermore, the reasonable range of subgrade modulus for different traffic levels was proposed for typical combinations of pavement with different thickness.