车辆移动荷载下黏弹性沥青路面的弹性等效方法

The mechanical model adopted in the specification of asphalt pavement design is the elastic multi⁃layered medium subjected to static load. However, the real vehicle load is a moving load, and the asphalt layers appear to be viscoelastic. How to select the appropriate elastic modulus in the pavement design so as to approximate the mechanical behavior of the viscoelastic multi⁃layered medium under the moving load is the key issue. First, the analytical solution for the mechanical responses of elastic / viscoelastic multi⁃layered medium under moving load was derived, and the theoretical relationship between mechanical responses and modulus of each layer was obtained. Then, based on the theoretical relationship, the equivalence principle and process of the elastic modulus were proposed; taking the viscoelastic three⁃ layered medium as an example, the moduli and the distributions of the mechanical responses before and after the equivalence were compared to verify the effectiveness of the elastic equivalence method. Finally, the viscoelastic parameters of each asphalt layer, temperature and vehicle speed were set as the input, and the equivalent elastic moduli were considered as the output. The prediction model for equivalent elastic moduli was established based on the artificial neural network. The results show that the equivalent elastic moduli can numerically reflect the properties of the viscoelastic layers. The distributions of the mechanical responses before and after the equivalence are basically the same, validating that this method can effectively equate the viscoelastic multi⁃layered medium under moving load to the elastic multi⁃layered medium under static load. The prediction model for the equivalent elastic moduli can provide accurate mechanical parameters for the asphalt pavement design.