The FEM Analysis On Asphalt Pavement Of Reinforced Concrete Bridge Deck

Asphalt pavement is playing an important role in bridge deck system. On one hand, it can distribute load and support force with bridge deck; on the other hand, it is a protective layer and the bridge deck structure of the joint force level. Good design of bridge deck can not only provide a good road performance, but also improve the durability of bridge structure. Although China's bridge construction has made remarkable achievements, in the pavement design and construction, only some experiences were adopted. Asphalt pavement, which was only treated as the subsidiary structure of bridge, generally do not make a special calculation and analysis, and current Codes also just provide guidance notes on thickness and construction, there are not any design theory and index to dependent on.Asphalt concrete pavement of the bridge is in a very complex stress state, the mechanical responses are not only confined by its own materials, but also by environmental temperature and load conditions. For these reasons, in the analysis on the pavement, the effects of various factors must be taken into consideration. Based on the finite element method in this paper, the elastic theoretical analysis by the Ansys software was carried out. The vertical deformation, principal stress, principal strain and maximum shear stress distribution of the bridge asphalt concrete pavement at static loads and moving loads were obtained, while the impact of parameters, such as temperature, overload and horizontal force, are also taken into account in order to draw corresponding mechanical laws. Secondly, based on the theory of viscoelasticity, the basic theory of dynamics and finite element method, the results of vertical deformation, stress and strain under haversine load were obtained. The effect of different temperature was investigated. Finally, considering the mechanical behavior of pavement, and taking into the existing asphalt pavement design specifications of the bridge deck at home and abroad, the asphalt concrete pavement design methods were explored.The results showed that the mechanical properties of asphalt pavement were different from the highway asphalt pavement. The maximum flexural tensile stress and the maximum flexural tensile strain occurred on pavement surface, and the maximum shear stress increased with the depth of pavement, yet after reaching a certain depth, it decreased with the increase of depth. The mechanical response of the pavement under the moving loads was similar to the results of static loads, but with a larger discrepancy in magnitude. The viscoelastic model is established, and the results showed that the mechanical response of pavement appeared lag phenomenon, but mechanical parameters distribution was similar with the linear.Based on the results of the analysis on asphalt concrete pavement, the causes of bridge deck disease from the perspective of the corresponding mechanical index were revealed. Finally, the corresponding designs of asphalt concrete pavement control index and design ideas were proposed.