English：

Based on a upgrade and renovation project, the BISAR program analysis method is used tostudy the impact of vehicle overload on the asphalt pavement structure of the expressway. The changes inroad surface deflection, tensile stress and strain at the bottom of the layer, compressive stress and strainat the top of the layer, and pavement shear stress and strain are analyzed. The research results indicatethat with the increase of axle load, the road surface deflection increases linearly, and the bending tensilestress increases accordingly. The compressive stress, tensile stress, compressive strain, and tensile strainof the road surface structure increase gradually. When the axle load is different, compared to the ratedaxle load, the compressive stress and compressive strain on the road structure significantly increase whenthe axle load is 225kN. As the axle load increases, the shear stress and strain of the road surfacestructure under the center of the wheel gap and the edge of the wheel track gradually increase. In actualexpressway upgrading and renovation projects, it is recommended to increase the structural strength of thepavement structure within a depth range of 2.5 ~ 10cm, or increase the material stiffness. At the sametime, overloading of vehicles is prohibited to control the damage to the highway pavement structure.