Research On Dynamic Interaction Of Vehicle-Asphalt Pavement Structure System And The Pavement Damage Mechanism

The pavement roughness will cause vehicle body vibration which in turn exerts dynamic load on the road.The interaction between vehicle and road surface has great influence on the damage of pavement structure.With the development of regional economy and the continuous improvement of highway infrastructure and vehicle performance,vehicle composition is developing towards high speed and heavy load.The vehicle dynamic load caused by pavement roughness can not be ignored.And this dynamic load will accelerate the pavement damage and failure,which will result in the more rapid deterioration of pavement evenness and thus form a vicious circle.Therefore,there is a coupling effect between pavement evenness deterioration and vehicle dynamic load.Based on the coupling effect,this paper made a thorough study of the vehicle dynamic load,the pavement dynamic response and its damage mechanism on the condition of vehicle-road interaction by means of the combination of theoretical modeling and numerical analysis.The main work had been done in the following aspects:(1)Considering the coupling effect between vehicle vibration and asphalt pavement structure vibration,three dynamic analysis models of vehicle-pavement structure interaction were established.The corresponding solution program was developed by directly inputing the pavement roughness to the dynamic balance equation of the vehicle-road system.The advantages and disadvantages of these three models in solving vehicle random dynamic loads were analyzed.Then the characteristics of vehicle dynamic load were studied and the time history of random dynamic load under different conditions was obtained based on the whole vehicle model which had higher accuracy.(2)The Fortran language was used to develop a moving random load subroutine VDLOAD which was related to the pavement roughness.Then a three-dimensional finite element dynamic analysis model of asphalt pavement structure was established.Based on this model,the dynamic response law of asphalt pavement structure and its influencing factors under vehicle-road interaction were studied systematically.(3)Based on the Shell permanent deformation theory,the permanent deformation calculating equation of asphalt pavement under the long-term action of vehicle random dynamic load was derived.And the pavement evenness deterioration equation was also derived.Thus a dynamic analysis model of vehicle-road interaction considering the pavement evenness deterioration was established.Based on the Matlab platform,a solution program IVP was developed.Combined with field test and numerical simulation results,the reliability of the model and its solution procedure was verified.Then the vehicle-road interaction law was studied under the condition of repeated axle load.And the nonlinear evolution law of vehicle dynamic load with the number of axle loads was also presented.(4)By introducing the effect of dynamic load to Miner linear fatigue damage evolution equation,the fatigue damage evolution model in each layer of asphalt pavement structure was established under the condition of vehicle-road interaction.And the corresponding solution program was developed to study the evolution rule of fatigue damage and permanent deformation of asphalt pavement under the condition of vehicle-road interaction.The results show that the fatigue damage evolution of asphalt pavement and the cumulative rate of permanent deformation were faster and showing nonlinearity after taking into account the vehicle-road interaction.The research results are helpful to enrich the theoretical foundation of the dynamic interaction of vehicle pavement and clarify the mechanism of vehicle dynamic load accelerating the asphalt pavement damage,thus laying a foundation for the dynamic design of asphalt pavement structure.