Nonlinear Analysis Of Inverted Asphalt Pavement

At present,domestic high-grade pavements are mainly semi-rigid asphalt pavements.Semi-rigid asphalt pavements have a series of advantages such as good integrity,high rigidity and strong carrying capacity,but semi-rigid base layers are prone to reflection cracks,especially in summer.In areas with large rainfall,the phenomenon of reflection cracks is more significant.In order to reduce the early failure behavior of semi-rigid base asphalt pavement,inverted asphalt pavement emerges as the times require,by adding a level between the semi-rigid base layer and the asphalt surface layer.It is equipped with a gravel transition layer to suppress the upward expansion of the reflective crack.However,the graded crushed stone material is a pellet material,and its rebound modulus exhibits a stress-dependent and nonlinear behavior,and its strength and rigidity are much lower than that of the semi-rigid base layer.Material strength and stiffness.Therefore,based on the infinite element,the infinite element model of inverted asphalt pavement is used to analyze the mechanical response of graded crushed stone nonlinear to inverted asphalt pavement.The main work and achievements are as follows:(1)Based on ABAQUS,the finite element axisymmetric model of inverted asphalt pavement with horizontal dimension of 12r~20r and vertical dimension of 30r~50r is established to analyze the influence of different finite element regions on the mechanical response of pavement.The software BISAR and KENPAVE calculation results are reference values,to determine the reasonable finite element area size of the inverted asphalt pavement.Furthermore,establishing a three-dimensional finite element model,to analyze the difference between the calculation results of the axisymmetric model and the three-dimensional finite element model,to make sure the rationality of three-dimensional finite element model..(2)Based on ABAQUS software,the infinite element model of inverted asphalt pavement is established.The reliability of the static infinite element model is verified by the elastic layer theory software.The reliability of the dynamic infinite element model established by semi-analytical solution under the surface load of Eason semiinfinite space,and the mechanical response difference of the inverted asphalt pavement under the action of vertical load and horizontal dynamic load of moving load and half sine wave load is compared respectively.The infinite element model is compared.The superiority of road dynamic analysis.(3)The Uzan-Witczak graded crushed stone nonlinear model was written in FORTRAN language.The influence of the non-linearity of the graded crushed stone on the mechanical response of the inverted asphalt pavement under the moving load was analyzed.The PAVE calculation results are reference values,and the reliability of the Uzan-Witczak graded crushed stone nonlinear model established by the ABAQUS material user subroutine UMAT is verified.The effects of non-linearity of graded crushed stone on the mechanical response of inverted asphalt pavement under different grades of gravel thickness and different loads are analyzed.