Abstract:

In order to reveal the mechanism of water-induced damage to asphalt pavement,a three-layer surface course-base course-subgrade physical model is established based on the Biot´s dynamic consolidation theory,and the governing equations of the three layers are deduced for the saturated asphalt pavement under moving traffic loads. Then,by utilizing the Fourier series expansion and the Fourier transform,the semi-analytical solution and the numerical solution are obtained for multiple physical fields in the surface course. Moreover,the dry pavement is compared with the saturated one in terms of stress distribution and pore water pressure distribution,and the effect of drainage boundary condition at the surface course bottom on the dynamic response of pavement as well as the effect of the shear modulus of pavement on the pore water pressure distribution is analyzed. It is found that,for the saturated asphalt pavement,higher tensile stress and larger tensile stress area are generated under moving traffic loads and that fully drained boundary greatly affects the distributions and values of pore water pressure and pore water velocity in the surface course with high permeability. However,it only has a slight effect on the surface course with low permeability,except for the small region near the surface course bottom. It is also found that the maximum pore water pressure decreases with the increase in the shear modulus of the surface course and the base course.

Key words: saturated asphalt pavement, drainage boundary, moving traffic load, dynamic response, Biot´s consolidation theory