Abstract
In July, 2004, an embankment behind a vertical seawall was damaged due to storm waves from Typhoon No. 8 on Hokkaido's Pacific coast, and railway services were suspended as a result. In this research, hydraulic model tests with irregular waves were conducted on a scale of 1/40 to clarify the characteristics of wave overtopping on vertical seawalls with replication of the wave and tidal conditions prevailing when the 2004 damage occurred. The patterns of rapid flow generated by wave overtopping were examined for the maximum condition of the irregular wave train. The velocity and thickness of the rapid flow was also reproduced by dumping water from an upper tank on a scale of 1/4. The scouring pattern was shown by the action of 30 instance of rapid flow onto the cement-reinforced model embankment. The test results showed that scouring of the model embankment was similar to that observed with the prototype.
