Study on the Method to Calculate Rutting of Asphalt Pavement Based on the Dynamic Load Coupled between the Road and Vehicle

By measuring the roughness of high-grade asphalt pavement, the time domain model of roughness based on international roughness index (IRI) was established by Inverse Discrete Fourier Transform(IDFT), which realizes the simulation of road roughness. The multiple-degree-of-freedom (MDOF) vehicle model was founded making use of the Dynamic Simulation software ADAMS. And with the time domain model, dynamic load spectrums for different grade pavements and different speeds were obtained by calculating dynamic load. Based on mathematical statistical analysis for load spectrums at different speeds and the influence of vehicle's actual loading condition and intermissive time, dynamic load models for different grade pavements were obtained. Combined finite element technology and the visco-elastic-plastic theory of asphalt mixture with the software ANSYS, the two-dimensional finite model of pavement structure was established. Considering the material characteristic of nonlinear, the method of calculating asphalt pavement rutting was put forward. The error is less than 10% between theoretical value and practical measurement rutting data of Handan-Changzhi highway. The result indicates that the method of rutting prediction, which based on the time domain model of roughness and the dynamic load coupled between pavement and vehicle is reasonable and reliable.