A MODEL TO STUDY THE DYNAMIC RESPONSE OF VISCO-ELASTIC LAYERED SYSTEM UNDER MOVING LOAD

Researches on the dynamic response of asphalt pavement under traffic loads became a hot issue in recent years, which is the basis to establish the dynamic design system for asphalt pavement. Based on the continuum dynamics and linear theory, an asphalt pavement dynamic model is established, treating a vehicle load as a moving load, and disposing the asphalt pavement structure as a layered system, and regarding the road material as visco-elastic material . The wheel load is treated as a cyclic loading whose spacing is large enough in the model. Using Fourier transform technique, the dynamic response under a moving wheel load with arbitrary form could be obtained, based on solving the dynamic response of asphalt pavement under a moving harmonic load. Taking a typical semi-rigid asphalt pavement as an example, the dynamic response regulations are studied, and the calculated results are compared with the accelerated pavement testing(APT) results. The calculated results are consistent with the test results on the strain time relationship, the lateral distribution of the dynamic response under the action of the wheel, and the maximum strain at the bottom of the asphalt surface layer, which prove the reliability of the model.