Numerical Simulation Analysis Of Asphalt Pavement Under Traffic Load

The current design specifications and research techniques for pavement in China were mainly based on elastic theory of layered material, which assumed deformation between two layers was continuous. The traffic load were generally simplified as single load or constant continuous load, which could not refect the characteristic of traffic. In fact, the state of contact between two layers was between absolutely slippery and whole continuous. The difference between theoretical assumption and practical engineering application had directly influence on the outcome of pavement research. Therefore, the paper strived to build a refined model, which could reflect the realistic physical state of pavement, to analyze the pavement structure.The paper took semi-rigid base asphalt pavement as the main research object and carried out a series of numerical simulation analysis from the general to the particular by finite elemet method. Firstly, a Temperature Prediction Model (TPM) of asphalt pavement under the circumstance of cyclic high temperature was carried out in order to provide the essential data for the Rut Prediction Model (RPM) subsequently.Secondly, the relations of rut depth, traffic volume and vehicle load in various conditions were studied in RPM. A refined load function of traffic was built in this model and the influence of traffic volume and moving vehicle was taken into consideration. The temperature sensitivity and creep property of asphalt were represented by time-depending creep constitutive model affected by temperature. The similarities and differences between asphalt pavement and composite pavement were analyzed in the end of this chapter.Thirdly, the phenomenon that the mechanical property of cement stabilized macadam had great difference before and after injury brought to the forefront. Asphalt pavement under continuous cycle load was modeled to study stress change and deformational behavior. The performance degradation of cement-stabilized macadam was reflected by decline of elastic modulus. The analysis included numerical simulation test for the combination of light and heavy load to study the influence of load change on the rut.Finally, the paper took the state of contact sufaces betweem different layers and bottom-up crack into account and analysed the mechanical response of asphalt pavement under moving load through3D FEM. The change rule of deflection, stress distribution and Crack Mouth Opening Displacement (CMOD) in different contact states was summarized in the end.The paper applied three kinds of load to different research objects. The change of temperature, performance degradation of material and structure and contact state were considered during study. All things considered, the simulation was able to draw scientific and reliable results and provided the theoretical basis for design and maintenance of pavement.