Analytical study of the dynamic response of a double-beam model for a geosynthetic-reinforced embankment under traffic loads

In this paper, a double-beam model of a composite working system including an upper pavement structure under traffic loads, an embankment fill layer, a geosynthetic-reinforced mattress, and the lower soft soil over the roadbed is developed. In the model, the reinforced mattress layer surrounded by viscoelastic materials has been assumed to have finite bending stiffness and carry the self-weight of embankment fill and the transferred traffic load. Furthermore, the pavement structure and the geosynthetic-reinforced layer have been respectively idealized as the upper typical Euler-Bernoulli beam and the lower modified Euler-Bernoulli beam supported by a series of discretely distributed spring-dashpot systems with different stiffnesses and damping coefficients. Based on these assumptions, governing differential equations for the response of the double-beam system are derived by the perturbation theory. Finally, a parametric study has been undertaken to inquire the influence of the flexural rigidities ratio of two beams, the stiffness ratio of upper and lower soil layers, the height of the upper soil layer, velocity of the traffic load, and the damping ratio.