Dynamic Response Of Perpetual Pavement Under Non-uniform Moving Load

Along with the rapid development of highways, the widespread premature failure and decreasing service life have become one of the key factors which restrict the further development of asphalt pavements. Foreign practices have proved that constructing perpetual pavement is an effective approach to solve premature failure and increase the service life of asphalt pavement. However, there is few domestic research and practice on perpetual pavements.Many recent researches have indicated that the contact pressure between tire and pavement is highly complex. It is different from the uniformly distributed vertical stress distributions traditionally used for pavement analysis. In this paper,two types of simplified load models have been put forward according to the tire tread patterns. The finite element program ANSYS was selected to analyze the response of perpetual pavements.under the two moving modelled loads. The effects of axle load,vehicle speed and material properties were studied,and the effects of vehicle load on permanent deformation and fatigue crack were also discussed. Theory is established as well as applying horizontal load with SURF154,We consider the influence to the perpetual pavements when different horizontal loads works together with the vertical load.The response of the pavement under different load magnitudes and load patterns was obtained through finite element method. The results show that the horizontal loads have a big influence on pavement structure within 8 cm.In my country,the semi-rigid type base is destroyed before asphalt surface under the temperature and load,which make the destruction of pavement structure in advance.First,this paper calculate the asphalt surface thickness of different axle mass abroad Second,consulting the theory of asphalt layer critical limited stress and adopting 0.35 stress level to control the fatigue destruction for cement stabilized granular material,this paper calculate the semi-rigid layer tension stress of different axle mass,vehicle speed and asphalt thickness with the perpetual pavements base on semi-rigid base. In the different condition,this paper analyse the principle and gain the minimum asphalt thickness within the fatigue destruction of semi-rigid type base.