Abstract:

The three dimensional vibration of pavement and double-layered subgrade coupled system subjected to a rectangular moving load are investigated analytically. The pavement-subgrade interaction is considered, and the subgrade is divided into an elastic single-phase layer and a saturated soil layer with the underground water level as their border. By employing Lame decomposition theorem of displacement field and potential functions, the governing equations of the system are solved in the transformed field domains of moving space. Considering the mixed boundary condition at the upper surface，the fixed boundary condition at the lowest surface and that the stress and displacement at the interface of the layers are continuous，analytical solutions of vertical displacement and pore pressure in the form of integral are derived using the Fourier transform and the inverse Fourier transform. Numerical results are obtained by using IFFT algorithm and adaptive quadrature algorithm. Reference is made for analyzing dynamic responses of subgrades.

Key words: Fourier transform, rectangular load, pavement and double-layered subgrade coupled system, 3D vibration