Evaluating Influence Depth of Light Weight Deflectometer through Finite Element Modeling

摘要

The light-weight deflectometer (LWD), which is the portable version of the common falling weight deflectometer (FWD), has been gaining popularity due to the ease of use and familiarity of pavement community to the deflection-based concepts. LWD imparts a pulse load to the surface of a soil layer through a circular plate to measure the soil surface deflection and to estimate the effective modulus of the underlying system. An extensive finite element modeling was performed to study the mechanism of two common types of LWDs during quality control of unbound pavement materials. The performance of the LWDs was evaluated under various loading conditions, different plate sizes and a diverse range of geomaterial properties. The influence depth was studied using both stress and strain criteria. The nonlinear constitutive model parameters seem to have significant influence on the measured influence depth of both devices. However, different functional properties of each device found to be the source of variations in the results.