SEMI-ANALYTICAL SOLUTION FOR DYNAMIC RESPONSE OF ANISOTROPIC LAYERED FOUNDATION-FLEXIBLE PAVEMENT STRUCTURE UNDER MOVING LOADS

A semi-analytical solution for the dynamic response of a flexible pavement structure on an anisotropic layered foundation under a moving load is proposed. Based on the theory of soil-structure interaction, a road-foundation coupling model for the flexible pavement and layered foundation is established. A wavenumber finite element model is established for the near-field road structure. Based on the precise integration and spectral element method, a novel spectral element model is established for the far-field foundation. According to the substructure method, the boundary conditions at near-far field coupling interface are determined, and the near-field and far-field structures are coupled together. Using fast Fourier transform, the dynamic response of the flexible pavement in the time and space domain can be obtained. The proposed method can consider the geometric characteristics of the road structure and take the stratification and anisotropy of foundation into account. The dimension of the near-field wavenumber finite element model is not affected by the number and thickness of foundation layers, and the computational result is stable. Both the validity and rationality of the proposed method are verified by comparing with the analytical solutions. Numerical examples are presented to reflect the difference between the dynamic responses obtained by using the road-foundation coupling model and previous overall layered model, and the effect of elastic modulus of road layer is also discussed.