Numerical Simulation Analysis Of Mechanical Effect Of Long Life Pavement Under Semi-rigid Base Mode

Under the action of increasing traffic volume and heavy load vehicles,asphalt pavement structure produces typical pavement damage,which makes the pavement structure in service quickly enter the damage stage and greatly shorten its service life.By analyzing the research status of long-life pavement at home and abroad,this paper determines the necessity of research on long-life pavement under semi-rigid base mode,and further proposes to conduct regional characteristic demarcation for asphalt pavement in cold region,aiming at analyzing the response of mechanical properties of each structural layer of pavement structure under the action of various influencing factors.This paper provides guidance research for the structural optimization of long-life asphalt pavement and the extension of pavement service life under semi-rigid base mode.In this paper,the finite element software ABAQUS was used to construct a three-dimensional model of typical semi-rigid asphalt pavement with a base.By comparing the mechanical responses of pavement structure under dynamic and static loads,it was found that the amplitude under dynamic loads was close to the mechanical responses under static loads.In order to approach the actual situation of the road surface,the subprogram is used to define the dynamic load,and the corresponding mechanical properties of the pavement structure are analyzed.The typical pavement structure meets the requirements of the bottom tensile strain of the asphalt mixture and the stiffiiess strain of the top surface of the roadbed.Multi-level comparative analysis was carried out on the size of pavement load,thickness of each layer and modulus to explore the influence degree of influencing factors on pavement structural design indicators,and the response law of pavement structural layer mechanical indicators under the change of influencing factors was obtained.According to the temperature field demand theory,a temperature field model of semi-rigid asphalt pavement was built.The temperature changes of a typical day in cold region in summer were measured to verify the temperature field constructed.Consider cold and summer heat and load under the condition of coupling effect,the analysis of typical day the most adverse temperature time pavement structure of asphalt mixture layer bottom tensile strain and shear stress,temperature and load together under the influence of pavement structure in the bottom of the asphalt mixture layer under the tensile strain corresponding to the high and low temperature time of micro strain in 90 and 80 micro strain level,the results show that the environment temperature load coupling effects on the mechanical performance of pavement is higher than the load change on the influence of mechanical response.Regulated the static way on the road surface pavement structure under load cumulative effect of permanent deformation calculation,with the cumulative traffic volume increase,respectively under the cumulative action of horizontal loading times more permanent deformation,found that plastic deformation accumulated rapidly in the early,on the accumulated deformation ratio is greater than the late,among them 20 million times action number of the second half of the rigid pavement structure deformation within 15 mm.