Dynamic elastic analysis of flexible pavements under moving vehicles: a semi-analytical finite element treatment

Semi-analytical finite element method has great advantages in computational efficiency compared with three-dimensional, because it only requires a two-dimensional mesh in the cross-section by incorporating the Fourier series along the third dimension. This study utilised the method to analyse pavement responses induced by moving vehicles. Combined with the structural property of pavement, the method is improved in terms of meshing and boundary conditions based on existing research. Using the Fourier series to represent loading functions along the driving direction, the load motion can be expressed as the translation of trigonometric functions. Spring element is applied at bottom to simulate the soil support, and viscous element is applied at vertical boundary to control the interference of reflected wave. The whole algorithm was realised by MATLAB programming. This algorithm was first used to analyse a layered structure under a rectangular load. Its accuracy and efficiency were verified by comparing it with a three-dimensional finite element model in ABAQUS. Then this algorithm was utilised to simulate a test road under a moving truck. The material assembly used the parameters calibrated by several nondestructive tests. Analysis results were compared with the field monitor of sensors for verification. This study also has some reference value about applying semi-analytical finite element method in pavement engineering.