Dynamic Response Of Asphalt Pavement Subjected To The Coupling Action Of Moisture-Loading

The serious premature failures occurred on the asphalt pavement after shortly opening to the traffic in recent years, such as inside reveling, cavity, pump slurry, net-shaped crack and rut depth. The moisture damage reduces pavement performance, increases road maintenance costs and causes huge losses to construction funds.Research shows that the pore water pressure of the inner structure of asphalt pavement under the coupled water-vehicle loading action is the main reason that results in water damage of asphalt pavement. The domestic and international researches have a little about analysis and research of the aspects of mechanical mechanism under the coupled water-vehicle loading action.Firstly, based on the theory of porous media and Biot, the asphalt pavement has been seen as the theoretical and ideal fluid and solid two-phase porous media, take the problem of withstand water-vehicle load coupling reaction of the asphalt pavement as the problem of dynamic analysis of saturated porous media, the finite element software ADINA is used to simulate the saturated asphalt pavement under the dynamic action of vehicle. The time history variations of pore water pressure, vertical displacement, vertical stress and horizontal stress for the inner structured asphalt pavement are analyzed respectively. Calculation results indicate that there is a reversion between positive and negative pore pressure in the inner asphalt pavement under the dynamic action of vehicle, which will accelerate the appearing of moisture damage.Secondly, the sensitivity parameters of saturated asphalt pavement under the dynamic action of vehicle are analyzed by finite element methods based on elastic mechanics. It is discussed that the resilient modulus of surface, base, subgrade have influence on the maximal deflection of the road surface, the pore water pressure, the radial stress of the base bottom and the sub-base bottom.Thirdly, the paper emphatically analyzes the variations of pore water pressure and maximal surface deflection of the inner structure of asphalt pavement under the coupled water-vehicle loading action by means of combination of asphalt pavement engineering examples. Based on the analysis mentioned above, the reasonable design of asphalt pavement structure is proposed. Finally, elastic-plastic yield criterion of Mohr-Coulomb model is used to simulate the characters of soft clay ground, cushion and composite foundation. Based on elastic-plastic mechanics, the time history variations of pore water pressure and vertical displacement for the inner structured asphalt pavement on the soft clay ground are analyzed by finite element methods.