3D Spectral Element Solution of Multilayered Half-Space Medium with Harmonic Moving Load: Effect of Layer, Interlayer, and Loading Properties on Dynamic Response of Medium

Abstract

The road pavement is a typical three-dimensional (3D) multilayered half-space medium, which consists of the surface courses, base courses, and soil subgrade/foundation. It is critical to understand the dynamic response of the road pavement under vehicular loads for improving structural design efficiency. The actual vehicular loads can be simulated as a harmonic moving load. In general, there are several methods to analyze the dynamic response of the multilayered half-space medium under harmonic moving loads, such as the boundary element method (BEM) and the finite-element method (FEM). However, the previously mentioned methods might face some unavoidable problems, for example, the numerical overflow, when the thickness of the medium is thicker, which causes the wrong result or long computing time. Therefore, the objective of this study is to develop a precise solution to solve the dynamic response of the 3D multilayered half-space medium under a harmonic moving load. In this study, a new type of 3D spectral element method (SEM) was developed and applied to the dynamic response analysis. Details of the mathematical derivation, implementation, and verification were demonstrated in the current paper. Subsequent numerical results, based on a layered road pavement structure constructed on a soil foundation, indicated that both the load speed and the frequency, the damping ratio of the structural materials, and the interlayer condition significantly impacted on the dynamic response of the structure under vehicular loads.