The Dynamic Analysis Of Asphalt Pavement Under The Spectral Element Method

The vehicle loads are always the moving loads while it carrying the frequency due to the surface roughness of the pavement and vibration of the vehicle structure.Thus it is hard to satisfied that applied the static load to design the asphalt pavement structure.Besides,the materials have the obvious transversely isotropic due to the asphalt mixture,gravel and subgrade soil constructed and compacted by complex stress.So there existing the limits in theory of multiple isotropic elastic medium for designing and analyzing.The paper would separately built the dynamic model of homogeneous isotropic asphalt pavement and transversely isotropic asphalt pavement,and utilizing the Spectral Element Method to analyze the asphalt pavement dynamic response induced by moving load.This article launches the research from following aspects:(1)A layered elastic system model of homogeneous isotropic asphalt pavement under moving load is established,and the effect of load moving velocity,load frequency and interlayer contact condition on dynamic response is studied by means of Spectral Element Method.The results show that,the vertical compressive stress at the top of the middle and bottom layers of the asphalt and the horizontal tensile stress at the bottom of the base layer increase with the increase of the moving speed and the vibration frequency of the moving load.The worse interlayer contact conditions between the base and asphalt layers would cause the vertical compressive stress at the top of the middle and bottom layers of the asphalt decrease slightly,while the horizontal tensile stress at the bottom of the base layer increase significantly.(2)The layered elastic system model of the transversely isotropic asphalt pavement under the action of moving loads is established.The Spectral Element Method is used to study the transverse isotropy of the asphalt layer under the different load moving velocity,frequency and the interlayer contact conditions.The results show that the smaller the transverse isotropy coefficient of the asphalt layer,the greater the vertical compressive stress at the top of the middle and bottom layers of the asphalt and the horizontal tensile stress at the bottom of the base layer,the greater the velocity and the frequency,the dynamic response would be more sensitive to the transversely isotropy of asphalt layer.The research of this paper can better characterize the regulation of mechanicalbehavior of the pavements under the moving loads,which is of great significance to improve and enhance the pavement design theory.