Calculation Method and Influence Law of Pavement Rut Under Dynamic Load

摘要

Based on vehicle dynamic loading, the rut calculation method is put forward, the influence law of pavement rut is obtained, and the rutting prediction for the test road was performed by employing this method. The results indicated that there is little difference between calculated rutting value and the real one of the test roads, and the maximum error is 9 %. Moreover, their deformation shapes of rutting are almost the same as a whole. Therefore, the proposed rutting calculation method is feasible for the very complex problem of rutting calculation. The influence law of pavement rut under dynamic load was studied by using this method. The results showed that high temperature, heavy load, and slow speed have important effects on rutting damage of asphalt pavement. Under heavy loads, with the temperature higher than 50℃, the repetition times of axle load more than 10~6, and the tire pressure higher than 0.9 MPa, the rutting depth of pavement will increase dramatically. In addition, when the vehicle velocity is smaller than 40 km/h, the rutting depth of pavement will also increase obviously with the loading duration increasing (i.e., with the vehicle velocity reducing). At the early stage of the loading process, the rutting depth of pavement increases rapidly, and as the loading time passes by, the growth rate of rutting depth gradually slows down, and finally rutting depth approaches to a fixed value. Furthermore, high modulus asphalt concrete applied in the middle course can significantly enhance the anti-rutting performance of asphalt pavement, and the anti-rutting ability of asphalt pavement can also be improved by increasing the thickness of the semi-rigid bottom layer of the base and of the surface course properly, especially of the upper layer of the surface course.