Research On Influencing Factors Of Asphalt Pavement Deformation Based On Discrete Element

Asphalt pavement has been used more and more widely in our country due to its excellent performance.However,in the course of use,the deformation of the asphalt pavement seriously affects its performance,reduces the comfort of pavement driving,and also increases the cost of pavement maintenance.For this reason,based on the Discrete Element(DEM)method,this paper discusses the influence of coarse aggregate content,loading width,foundation softness,and foundation thickness on pavement deformation,and analyzes its mechanism from the perspective of the internal force chain of the pavement.It can provide a certain reference for solving the problem of road deformation.During the research process,the main work carried out and the conclusions obtained are as follows:(1)The principle of DEM method is explained through a simplest two-particle model,the main factors affecting the accuracy of DEM method simulation results are discussed,and the DEM simulation results of the simplest model are compared and verified with theoretical calculation results.It provides a theoretical basis for applying DEM method to asphalt mixture simulation.(2)According to the mechanical characteristics of the asphalt mixture in the indoor3 SCB test,the commonly used Burgers contact model was optimized,and the Burgers-Linear contact model was constructed,and the contact model was realized through the secondary development of PFC5.0.Then,by comparing the results of the indoor 3SCB test and the virtual 3SCB test,the accuracy of the new Burgers-Linear contact model was verified,and the meso-parameters of the Burgers-Linear contact model were determined.(3)The influence of coarse aggregate content and loading width on the deformation of asphalt pavement was discussed,and the pavement bearing capacity and the change law of deformation were summarized from the load-displacement curve and the change of uplift height,and then from the tension/compression contact transformation,The force chain in the asphalt pavement is analyzed in three aspects: the change of the number of main pressures and the distribution of cracks.The results show that the destructive strength of the pavement structure with high aggregate content is greater than that of the pavement structure with low aggregate content,but the load displacement when the uplift deformation occurs is smaller than that of the pavement with low aggregate content;the amount of principal pressure is the key to determining the bearing capacity of the pavement structure Factors: When the internal fracture of the pavement structure occurs,tensile failure is the main cause under the compression zone,and shear failure on both sides of the compression zone;with the increase of the loading width,the bearing capacity of the pavement structure increases,but the swelling height appears time Sooner.(4)In the asphalt pavement model containing the foundation layer,the influence of the foundation layer on the deformation of the asphalt pavement is discussed by changing the stiffness and thickness of the foundation layer.It also summarizes the pavement load-bearing capacity and deformation rules from the load-displacement curve and the uplift height change.Then,the force chain in the asphalt pavement is affected by the tension/compression contact conversion,the change in the number of main pressures,and the distribution of cracks.Carry out analysis and summary.The results show that in the presence of a weak foundation,as the loading displacement increases,the internal force of the pavement structure goes through three stages;as the stiffness of the foundation decreases,the internal force chain of the foundation structure changes from the upper rectangle to top to bottom In the triangular transformation,the weaker foundation and the pavement structure share the top load;the smaller the thickness of the weak foundation,the greater the bearing capacity of the pavement structure.