Abstract
In Niigata West Coast, decrease of nourished sand due to sand drift along the scour formed behind the submerged breakwaters has been a technical problem. In order to prevent the sand loss, two countermeasures of sand control dike and submerged groin have been experimentally installed to prevent nourished sand from falling into the scour and running off from the nourished zone. Effectiveness of the countermeasures has been verified by successive observations of current and seabed height. As the results, it is confirmed that the submerged groin is effective in preventing sand loss and decreasing current speed near the seabed. It is also confirmed that the sand control dike has a certain level of effectiveness in preventing the sand from falling into the scour.
