The Numerical Simulation Analysis On Load Crack Propagation Behavior And Influence Factors Of Asphalt Pavement

According to the data from expressway network of china, by the end of 2014, china has a total highway mileage of 4.4639 million km, including expressway mileage reached 111900km, first grade highway 85400km, the secondary highway 348400km, the asphalt pavement is the main type of pavement in our country’s grade highway. The crack is one of the common road diseases, at present the main method for crack simulation analysis is FEM, and the appearance of the XFEM method make the crack propagation simulation analysis is more close to the engineering practice.First of all, to summarize the common fracture mode and mechanism of crack propagation, and the form of XFEM. Desin the orthogonal experiment of SCB test, choose the evaluation index, determine the influencing factors and levels, and determine the plan of orthogonal experiment. To test the raw materials and design the proporation of asphalt mixtures, and make the SCB specimen for testing by the experiment plan, and to do orthogonal anaysis of the test results by SPSS 19.0 software. Second, make four types of asphalt mixture beams for creep experiment, and the mixture creep curve will be obtained. Fitting model parameters of Burgers by OriginPro 9.0 software, and compile user material subroutine UMAT based on the compiled Fortran platform, so the asphalt mixture parameters can be imported. To simulate and analyze the cracks extension process of SCB test with 8 mm,18 mm, and 28 mm crack by extended finite element method for different mixture, and compared with the experimental results, evaluate the effect of simulation with the method. Finally, to obtain pavement material parameters by experiment and specifications, and compare finite element calculation results with the BISAR calculation results of principal stress on the same model. To analyze the propagation rule of roadbase crack under the center load with different crack depth, crack width,structure layer thickness and modulus, axial load by extended finite element method. To analyze the rule of shear stress intensity factor and the crack propation under deflected load.To analyze the propagation rule of surface crack under the partial load with different crack depth, crack width, structure layer thickness and modulus. To analyze the multiple crack extension path under the load by extended finite element method and evaluate the simulation results. In order to provides a theoretical reference for maintenance and prevention the cracks of asphalt pavement.