抄録
The sliding safety factor of a breakwater in the deterministic wave and tidal level should be larger than 1. 2 in the present design method, but the safety degree may decrease due to the variation of the marine condition in global warming. The sliding failure probability of a breakwater during the life time can be evaluated by a reliability design method. The mean water rising may push up the sliding failure probability only in surf zone, where the incident wave height is proportional to the water depth. On the other hand, assuming the meteorologicaltide anomaly is related with the offshore wave height, the increase of the offshore wave height raises the sliding failure probability not only in deepwater but also in surf zone.
