Mechanical Analysis Of Rutting Causes Considering Temperature Field For Asphalt Pavement In Urban Road

With the rapid increasing of vehicles, the requirements on the quantity and quality of urban road system are rising. As one of the main reasons of damaged asphalt pavement in urban roads, the problem of asphalt pavement rutting caused more attention nowadays. Most of the existing study about asphalt pavement rutting is in constant temperature conditions, ignoring the influence of periodic changed climate and traffic conditions on the process of produce and development of asphalt pavement rutting.Firstly, the thesis focuses on investigation on the pavement cuttings in some of the main roads in Changsha. Exploring the reasons to cause the cuttings, the characteristics and influencing factors of it by combining the type and formation mechanism of the rut.Secondly, a three-dimensional finite element model of an asphalt pavement structure is established by ABAQUS software. The temperature boundary conditions of the model are based on the monthly average meteorological data in these years. Then the diurnal variation of temperature field of the asphalt pavement is analyzed by two subroutines, i.e. DFLUX and FILM. The results show that the changing of temperature would cause a large temperature gradient in thickness direction of the asphalt pavement structure surface, and cause unevenness and instability on the temperature of the pavement structure.Finally, the moving load has been implemented into ABAQUS by coding subroutines DLOAD and UTRACLOAD, the mechanical responses of pavement under different combinations of loads are calculated. Detailed study on the influencing factor such as temperature field, vehicle speed, horizontal load and ground pressure is further performed. Associating with the analysis of law of daily changing of rutting and the related influencing factor, the mechanism of rutting in the intersection of asphalt pavement is concluded. Results indicate that the drastically increased horizontal shear stress under horizontal load is the main reason for the rutting in the intersection of roads. The propagation of rutting has temperature range effect, the shear strength and modules of asphalt mixture decreases sharply when the temperature is above25degree which directly leads to the dramatic propagation of rutting. Both the horizontal stress and the amount of rutting decrease with the decreasing of vehicle speed, meanwhile, they are proportional to the index of horizontal load and the ground pressure.