Dynamic Stress Responses of Rough Pavement Resting on Layered Poroelastic Half-Space under Moving Traffic Load

To investigate the influence of pavement roughness on the dynamic stresses under traffic vehicles, a pavement resting on a layered poroelastic half-space is studied. The shape of pavement roughness is treated as a sine function of irregularity while the vehicle is modeled as a quarter-vehicle vibration system with two degrees of freedom (DOF). Based on the Biot's dynamic poroelastic theory, the time domain solutions of the homogeneous poroelastic half-space are obtained by Fourier transforms and inverse Fourier transforms. The time domain solutions of the layered poroelastic half-space are then presented using the transfer-matrix method. By regarding the top layer as a thin-plate and using the Kirchhoff's hypotheses, the vertical displacement and stress of the thin plate are calculated. The time domain solutions of the rigid pavement-layered poroelastic ground system are obtained based on the compatibility condition at the interface of the pavement-ground system. The dynamic effects of the load velocity, the wave length and the thickness of the plate are discussed, respectively. It is found that the roughness of the top plate significantly affects the dynamic stress response in the poroelastic layers when the vehicle velocity is below a critical value. In addition, the dynamic impact coefficient depends on the wave length of the roughness as well as the amplitude. The dynamic stress response caused by the roughness of pavement is evident and different from the dynamic stress response caused by vehicle weight. This study is intended to provide potential guidance for the design of a rigid pavement system.