Dynamic Displacement Response of Pavement Structure under Moving Vehicle Load

In order to study the dynamic displacement response law of pavement structure under driving load, a finite element model (FEM) of pavement structure is established by the theory of elastic layered system. Applying the random dynamic load of a vehicle to the FEM, the variation of vertical dynamic displacement in the structural test area is analyzed with changing thickness and modulus of the pavement layer, and a mathematical model of relationship between the peak dynamic displacement of the test area and parameters of the pavement structure layer is proposed to characterize the dynamic response of the pavement structure. Results of FEM calculations show that the peak dynamic displacement of the pavement test area decreases with an increase in the soil matrix modulus; what's more, the peak dynamic displacement is more sensitive to the soil matrix modulus than to other pavement layer parameters, and the mathematical relationship between them is logarithmic. Meanwhile, the peak dynamic displacement of the pavement test area is approximately linear with the thicknesses of the surface layer and the base layer, and is approximately logarithmic with the thickness of the subbase layer. However, the dynamic displacement curves of the test area with different surface layer moduli, base layer moduli and base layer moduli almost coincide, implying that they are not the main influencing factors of the dynamic displacement. The obtained results provide a basis for the detection of pavement bearing capacity.