Dynamic response of a flexible pavement submitted by impulsive loading

The present paper introduces results from measurements on site using a falling weight deflectometer (FWD). This apparatus is used for non-destructive testing of damaged pavement in order to estimate the elastic modulus of each layer. The basin of deflection induced by a controlled load can be determined with precision and can reflect the behavior of the pavement structure. The interpretation of data generated by FWD leans on inverse analysis processes. Data from FWD combined with the thickness of layers inform on the evolution of the Young's modulus of each layer of the structure along the studied road profile. This information can be also used to estimate its lifespan and possible repairs to be carried out.The resolution of the dynamic problem is implemented in a finite element software. The dynamic load was modeled from the real falling weight of the measuring apparatus. The numerical model includes absorbent boundaries to avoid all reflections. Results of in-situ measurements from the nine sensors were compared with the model. The comparison gives promising results, considering the difficulty in characterizing the mechanical parameters of the pavement. From this model, it will be obviously possible to develop an inverse analysis method to characterize the modulus of the layers and to identify the pavement defects.