Effects of Pavement-Falling Weight Deflectometer Interaction on Measured Pavement Response

In any linear elastic program used in backcalculation, a uniform pressure distribution is assumed for the applied load. As such, the loading system of any FWD should be designed so that the load transferred to the pavement is uniform. However, the pressure distribution is also affected by the pavement profile being impacted on. A finite element study has been carried out to determine the cases where the imparted load would or would not yield a uniform pressure distribution and to assess its significance on the measured and backcalculated parameters. The FWD-pavement interaction has little significance when rigid pavements are tested. For flexible pavements, the deflections from the first sensor may be affected by this interaction. The softer the pavement system, the more significant this interaction will be.