Dynamic Response Of Asphalt Pavement Supported By Uneven Subgrade

More and more road was constructed from the eithth five-plan. The highway mileage has increased 12,000 km in 2015, and the National Highway mileage has exceeded 125,000 km by the end of 2015. At present, more than 90% of roads are semi-rigid base in asphalt pavement. Due to the inhomogeneity of compaction and the variability of material, the road construction existed uncertainties. These uncertainties may cause the inhomogeneity of modulus and strength. After repeated vehicle loading, areas with weak stiffness may occur uneven settlement, and then, the bottom of the subbase would be void and fail ultimately.In view of this, this paper carried out a field modulus test, and established ?truck-pavement-uneven subgrade? dynamic interaction model to simulate dynamic response of asphalt pavemtn. The main work and conclusions are as follows:(1) According to the field test performed in Yaxue Road using PFWD(Portable Falling Weight Deflectometer, the same below), this paper analyzed the distribution of subgrade modulus and base modulus.The Lane Consistency Statistics Value of transverse and longitudinal were referenced to evaluate the modulus inhomogeneity quantitatively.(2) Based on the D?Alembert principal and viscoelastic thin plate theroy, this paper established ?Truck-pavement-subgrade with uneven modulus? and ?car-asphalt surface-subgrade with uneven deformation? models, and rewrote this two models in numeraical program so that the program can calculate the dynamic response of asphalt pavement with uneven subgrade.(3) Based on the advanced calculation program of uneven modulus, this paper calculated and analyzed the impact of subgrade modulus decrease characteristics, pavement structural characteristics, truck speed and axle load on dynamic response principle of pavement dynamic strain and deflection. According to analysis above, this paper proposed a prediction formula based on uneven modulus.(4) Based on the advanced calculation program of uneven deformation, this paper calculated and analyzed the impact of uneven settlement characteristics, pavement structural characteristics, truck speed and axle load on dynamic response principal of pavement dynamic strain and deflection. According to analysis above, this paper proposed a prediction formula based on uneven settlement.