Influence of Joint Load Transfer Capacity on HWD Deflection Response of Airport Cement Pavement and Void Determination

To enhance the scientific rigor and accuracy in detecting voids beneath cement concrete pavements in civil airports, a three-dimensional finite element model consisting of 3 × 3 slabs was established using finite element software based on the Winkler foundation model. The mechanical responses of the slab edge region under loading from the Heavy Weight Deflectometer (HWD) were systematically simulated. In this model, both the load transfer capabilities of various joint conditions — namely good, medium, secondary, and poor — and the configuration of voids beneath the slab were taken into account. The variation patterns of key mechanical indicators, including deflection value and deflection ratio, were analyzed. The results indicate that poorer joint load transfer capacity leads to larger deflection values and deflection ratios at the slab edge, whereas the deflection within the slab interior is less influenced by joint load transfer capacity. The model was validated using measured deflection data from multiple airports, demonstrating strong reliability and applicability. This study provides a theoretical foundation and technical reference for identifying voids beneath airport cement concrete slabs and for supporting maintenance decisions.