An Experimental Study on Changes of Sandy Beach Profiles Under the Effect of Submerged Breakwater

Submerged breakwaters have a good efficacy for nourishing sandy beaches and promoting the silting.The variations of sandy beach profiles under the effect of the submerged breakwaters are studied based on wave flume experiment and by taking the regular waves into account.In the experiment,a beach slope of 1/10 and 1/20 is respectively adopted.The evolution of the sandy beach is analyzed under the same water depth and different positions and top water depth of the submerged breakwater.The results show that the submerged breakwater exerts an obvious effect on the variation of sandy profile.If the water depth over the top of the breakwater keeps the same,the depth of the maximum scoured pit behind the breakwater can gradually increase with the breakwater shifting away from the coast,while the largest silting point moves shoreward.At the same position,the efficacy of the silting reduction decreases as the water depth over the breakwater top increases.The best efficacy of scouring prevention and silting reduction obtained from the experiment is that the submerged breakwater is placed ahead of the largest silting point of the case without the breakwater.