Structural Response of Asphalt Pavement under the Coupling Effect of Subgrade Permanent Deformation and Vehicle Load

Permanent deformation of loess subgrade is calculated under the condition of light and heavy vehicle running in respective lanes, which is the common traffic organization of high-grade highways. Based on repeated load triaxial test results, ABAQUS software and elastic mechanics method were used to analyze the stress of asphalt pavement structure under the coupling effect of subgrade permanent deformation and vehicle load in this paper. The results indicated that the maximum tensile stress on bottom of semi-rigid base was much bigger when considering the effect of subgrade permanent deformation. Permanent deformation of loess subgrade on condition of vehicle running in the lanes freely and tensile stress on bottom of semi-rigid base under the effect of permanent deformation were both calculated, which proved that the maximum tensile stress on bottom of semi-rigid base increased signally. The semi-rigid base cracked gradually under the coupling effect of subgrade permanent deformation and vehicle load, which could lead to the lower service level and reduced fatigue life of semi-rigid base asphalt pavement.