|
Abstract A series of hydraulic model tests of regular waves acting on movable sandy sloping beaches equip with detached submerged dikes and incline sea dikes were carried out to investigate their influences on the locations of wave breaking, the height of run-up, the rise of mean water level, the beach erosion, and the stabilization of submerged dike. Two types of sandy beaches, two sets of submerged dikes, and two kinds of incline sea dikes were used selectively in setting up the different layouts. The results show that the deployment of submerged dikes can cause the earlier breaking of incident waves, reduce the beach erosions and stabilize the sandy beach, and two sets of submerged dikes is better than one set. Such benefit is not dominant, however, when the distance between the shoreline and the location of dike is around one-half of wave length. Under the long term wave actions, the coarse sandy seabed can accumulate sands between the armor units, forms a sand bar and decline the anchorage force between the units, and that cause the armor units individually moved by the wave forces. In the evaluations of different shore protection layouts, the increase of second set of submerged dikes can largely reduce the coastal erosion, and arranging the opening of two sets of dikes in stagger way is better than in collinear way.
|