Vehicle-Road Coupling Dynamic Response Of Asphalt Pavement With Micro-Cracks Based On Discrete Element Method

Asphalt pavement is one of the use forms of high-grade pavement in our country.After a long period of use,the asphalt pavement will produce some cracks inside,which will seriously affect the service life and safety of the pavement.Through detection technology and computer automatic classification and collection of data such as the number and geometric characteristics of micro-cracks in the pavement,these data can be used in computer simulation of pavement micro-cracks in order to obtain true and accurate simulation data.The DEM(Discrete Element Method)can pay more attention to restoring the heterogeneous structure of asphalt pavement and the real distribution and geometric characteristics of micro-cracks in the pavement,and can deeply understand the influence of micro-cracks on the response of asphalt pavement,optimize the design of pavement structure and materials,and improve the durability and stability of pavement.The study on the influence law of microcracks on asphalt pavement can provide more scientific construction scheme and technical guidance for the construction personnel,so as to reduce the occurrence and development of microcracks on pavement.It is very important to study the influence law of microcracks on asphalt pavement to ensure the safety,comfort and durability of pavement.The main research work of the thesis is as follows:(1)Analyze the relationship between discrete element mesoscopic parameters and material macroscopic characteristics,calibrate the mesoscopic parameters of the pavement structure layer,obtain the tire dynamic load through MATLAB/Simulink,and put micro-cracks in the pavement model to construct a vehicle-road coupling with microcracks asphalt pavement model.(2)Design pavement experiment schemes under different working conditions,measure the vertical stress,horizontal stress and shear stress of each structural layer inside the pavement model,record the stress peak value of each working condition,and compare the influence of micro-cracks on the macroscopic response of the pavement.(3)Investigate the mesoscopic structure of pavement and observe the development of force chains at different stages.Record the distribution of normal forces in the force chains between the upper and lower layers of the pavement under different working conditions,and compare the results to determine the impact of micro-cracks on the pavement at the microscale level.(4)Analyze the displacement and stress cloud maps of asphalt pavement models containing micro-cracks at various stages.Examine the motion and stress states of particles inside the pavement under different working conditions,and compare the results to determine the impact of micro-cracks on the response of internal particles within the pavement.