Finite element analysis of effects of asphalt pavement distressrs on FWD dynamic deflection basin

Abstract

Falling weight deflectometer_FWD_ testing has been done extensively in the past to assess structural condition. Utilizing the deflections measured by the FWD, the resilient modulus of layers in the flexible pavement is determined using back calculation software packages. But the pavement distresses influence the validity of FWD dynamic deflection basin. This paper based on the theory of structural dynamics, the three dimensional dynamic finite element model was created. The influence of asphalt pavement distresses such as interlayer contact between surface course and base course, a single transverse pavement cracks, multiple-transverse cracks, longitudinal cracks and block crack on FWD dynamic deflection basin were analyzed using this model.The results show that the interlayer contact mainly affects the dynamic deflection of four surface deflection point. For single transverse cracks , the measured value of FWD is close to that of the pavement structure without cracks when the distance between the load centre of FWD and the cracks is greater than 1.1m. For longitudinal cracks , FWD dynamic deflection basin is not significantly different from that of pavement structure without cracks when the distance between loading and longitudinal cracks is greater than 0.35m.