Spectral element approach for forward models of 3D layered pavement

For the spectral analysis of the three-dimensional multi-layered pavement, 3D layer spectral element method is presented to solve the problems of bounded layer system subjected to a transient load pulse. In spectral element, each layer is treated as one spectral element. The wave propagation inside each layer element is achieved by the superposition of the incident wave and the reflection wave. Fast Fourier transformation is used to transform FWD datum from time domain to frequency domain. The accuracy and efficiency of 3D layer spectral element approach were verified by analyzing the Falling weight deflectometer(FWD) testing model with the spectral methods and the finite element method(FEM).