Abstract
Traffic hindrances were often caused by overtopping waves under storm wave conditions on coastal roads behind gently sloping seawalls. In this study, the damage risk of vehicles due to wave overtopping was revealed by the field observation data. Based on the results of hydraulic model experiments with irregular waves, the characteristics of wave overtopping water thickness, wave overtopping rate and the horizontal wave force on the vehicle were disclosed for three wave period conditions at the sea side road section. The relationship between maximum wave overtopping thickness and offshore wave height was shown for wave period conditions. In order to examine the stability of vehicles for the longest wave period condition, the wave pressure distribution was formulated as a function of the wave overtopping thickness on the road. The validity of the calculation formula was also confirmed by the sliding experiment of vehicles.
