Response Analysis For Asphalt Pavement Under Coupling Effects Of Vehicle Moving Load,Water And Temperature

In the real working environment,asphalt pavement is affected by vehicle load and environmental factors such as temperature and water at the same time.Many common road surface diseases are closely related to these coupling factors.The elastic layer theory is still the theoretical basis of the pavement calculation in Chinese pavement design guides.However,as a classical single-phase field theory,it cannot effectively reflect the effects of vehicle temperature and water on the pavement structure at the same time.While a large number of studies have proved that the influence of temperature and water on the pavement structure cannot be ignored.Therefore,the establishment of coupled field theoretical pavement models that can integrate vehicle,temperature,moisture and other factors to comprehensively analyze the asphalt pavement structure under the influence of multiple factors,has become one of the most popular topics in the theoretical analysis of pavement engineering.The transfer matrix method and the stiffness matrix method are the most classic and widely used solution methods for solving the layered pavement problem.However,when the matrix analysis method is used to deal with the layered body problem,matrix operation overflow,singular matrix,etc.sometimes appear in the calculation process.Based on the traditional matrix analysis method,this thesis will use the orthogonal vector function system and the DVP method(Dual variable and position method)to solve layered pavement problems.The presented method has a more concise derivation form,stable operation process and higher computational efficiency than before.Then with the help of the new method,the elastic layered pavement problem under moving load and the multi-field theoretical pavement problems will be solved.The main research contents of this paper are summarized as follows:(1)The improved transfer matrix method for solving the layered structure problem is introduced based on the orthogonal vector function system,and the analytical solution of layered half-space problem with imperfect interfaces is derived when the general circular uniform loads effect on the surface.According to the basic equations of the elastic layered half-space model,by using DVP method a new and more stable transfer matrix relation is derived under the orthogonal vector function system.In the numerical parts,the analytical solution is compared with the existing results to verify the correctness of the proposed method and the derived results.Finally,the influence of the interfacial coefficient on the calculation results under different interface models are analyzied.(2)According to Elastic-dynamics equations,the DVP method based on orthogonal function system is used to derive the mechanical response solution of a layered pavement under the circular surface load in the moving coordinate system.In the numerical parts,the correctness and rationality of the derivation results are verified through comparison examples.Further,the convergence of the results at different points is analyzed.Then the influences of the vehicle moving speed and the sliding interface between different layers on various mechanical responses are discussed through the above obtained analysis solution.(3)The three-dimensional layered saturated pavement model is established by using Boit consolidation theory combined with porous medium theory.According to the basic equation of Biot's consolidation problem and the seepage equilibrium equation of Darcy's law,DVP method based on orthogonal function system is used to derive the analytical solution of saturated poro-elastic pavement problem under the moving load.In the numerical parts,the pore water pressure and pore water flow speed in the pavement models are calculated under different working conditions.Then the influences of surface permeability and vehicle speed on the pavement pore water are analyzed.(4)Based on the flow-heat-solid theory,DVP method based on orthogonal function system is used to obtain the analytical solution of the coupled field pavement problem.Then,the difference between the results obtained through different field theorys is compared,and the analytical solution of the pavement model under the coupled field is verified at the same time.Finaly,the effects of vehicle moving speed,temperature and sliding interface are discussed based on the obtained analytic solutions of the coupled field pavement model.