Numerical Reconstruction of Port Apron Pavement Failure via a Coupled Overtopping-Inundation-Uplift Mechanism

To investigate the asphalt pavement failure observed on the apron at Gamman Pier, Busan Port, during Typhoon Maysak in September 2020, this study numerically reconstructed a coupled overtopping-inundation-uplift scenario. A CFD model using the Volume of Fluid (VOF) method was developed for an idealized cross section, and the pressure difference between the upper and lower pavement surfaces was compared for different gap widths at the coping concrete-pavement boundary. For the 5 cm gap condition, the mean uplift pressure over the evaluation segments ranged from 2.25 to 3.32 kPa, which did not exceed the self-weight pressure of a 15 cm thick asphalt pavement (3.60 kPa). In contrast, for the 1 cm gap condition, the mean uplift pressure ranged from 2.87 to 4.99 kPa, about 1.3 to 1.5 times larger than that for the 5 cm gap, and a localized net uplift zone exceeding the pavement self-weight was formed. This zone extended over approximately 2.06 m, and the corresponding maximum bending tensile stress was estimated to be 0.63 MPa. These results indicate that delayed drainage, base saturation, and weakened bonding at the coping concrete-pavement interface can promote uplift, delamination, and crack initiation under repeated overtopping loads. Therefore, the pavement failure at Gamman Pier is considered a plausible consequence of the coupled effects of overtopping, inundation, and uplift pressure under unfavorable local boundary conditions.