移动交通荷载下饱和沥青路面的水力耦合分析

为了解沥青路面的水损害机理,基于Biot动力固结理论,建立了移动交通荷载下“面层-基层-路基”三层体系的物理模型和水力耦合动力控制方程.利用Fourier级数展开、Fourier变换等方法获得了各路面结构层中各物理场分布的半解析解和数值解.经过对比分析干燥路面和饱和路面面层中的应力分布和孔隙水压力分布、路面面层底部排水条件对路面动力响应的影响以及路面剪切模量对孔隙水压力分布的影响,发现:相对于干燥弹性的沥青路面,饱和沥青路面在移动交通荷载的作用下会产生较高的拉应力,形成更大的拉应力区；完全排水边界会显著影响高渗透性路面内的孔隙水压力和孔隙水流速的分布和大小,但是对于低渗透性的路面而言,完全排水边界对孔隙水压力和孔隙水流速的分布和大小影响较弱,只在接近于面层底部的小区域范围内影响显著；最大孔隙水压力随着面层剪切模量的增大而有所降低；排水和不排水边界条件下的最大孔隙水压力都随着基层剪切模量的降低而有所增大.

Coupled Hydro-Mechanical Analysis of Saturated Asphalt Pavement Under Moving Traffic Loads

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.