Numerical Simulation Of Mechanical Behavior Of Asphalt Pavement Structure Under Non Uniformly Distributed Moving Wheel Load

Different from the circular uniform static load in the traditional asphalt pavement structure calculation,the actual tire has a strike pattern,its tire pavement contact stress is uneven,and the pavement load has mobility.Research on the influence of non-uniform moving load on pavement structure the development of numerical simulation describes the complexity of load in detail,and there is little research on such problems,which still needs in-depth research.Based on previous studies,considering the mobility of pavement load,the non-uniform distribution of ground stress and the viscoelasticity of asphalt material varying with load speed,the numerical analysis of mechanical response of asphalt pavement structure is carried out in this paper.The main work is as follows:(1)This paper discusses the design methods of asphalt pavement in Australia,Japan,France,Russia and other countries,as well as the evolution of load considerations in the design methods of asphalt pavement for highways and urban roads in China.This paper mainly analyzes the similarities and differences between different countries in the aspects of pavement structure,standard calculated axle load,calculated point position and the reasons for the differences;In particular,starting from the calculation points,the evolution process of asphalt pavement structure calculation points in China is compared horizontally and vertically,and the improvement direction of its structure calculation and its impact on the current asphalt pavement structure calculation are investigated.(2)Two special pavement structure computer programs everstressfe and 3D move analysis are selected for comparative analysis of numerical calculation of asphalt pavement structure under non-uniform load.By comparing the implementation principle,implementation technology and example discussion of the two two software products non-uniform load technology,the advantages and disadvantages of the two software products in non-uniform implementation technology are compared,and the effects of non-uniform load on road surface deflection,tensile strain in driving direction at the bottom of asphalt layer are discussed The influence of vertical compressive strain on the top of soil foundation lays a theoretical foundation for the analysis of non-uniform load.(3)Two programs,kenlayer and 3D move analysis,are selected to compare the moving load effect of asphalt pavement structure calculation.The implementation principles of viscoelasticity,moving load and solution configuration of the two programs are mainly compared,and the implementation technologies of moving load of the two two software products are compared through calculation examples under the action of single circular uniformly distributed moving load and double wheel uniaxial uniformly distributed moving load.The influence of different speeds and axle load types on asphalt pavement structure under moving load analysis is preliminarily discussed,which lays a theoretical foundation for the subsequent moving load analysis.(4)In this paper,the dynamic analysis of asphalt pavement structure under the same wheel load and different tire pavement contact stress distribution is carried out by using 3D move analysis program,and compared with the circular vertical uniform load case.The variation laws of the most unfavorable values of the tensile strain in the driving direction at the bottom of the asphalt layer and the vertical compressive strain at the top of the subgrade of the pavement structure under different tire pressures and driving speeds,as well as the variation laws of the mechanical responses at different calculation points in the tire width direction are analyzed,and the influence of the change of the location of the least favorable mechanical response points on the dynamic test and the current asphalt pavement structure design method is put forward.The research results obtained in this paper have certain guiding significance and practical value for the field dynamic test of asphalt pavement and the optimization of pavement structure design method.