Investigation On The Application Of Submerged Dyke In Project Of Beach Protection And Siltation Promotion

In recent decades, the power balance of World coast has been damaged due to various natural and man-made causes. Under the frequent role of tide and wave, coastline Continued erosion, beach flat height seriously decline, coast structure badly damaged, All of that affect people's life and production. So, it is important to study the Project of Beach Protection and Siltation Promotion in badly erosion coastline.Submerged dyke is a common offshore structure, which is widely used for band protection, Beach Protection and Siltation Promotion, flow-guided engineering and etc. On the one hand, submerged dyke can effectively decrease wave power which behind the dyke, increase the coastal structure safety factor; On the other hand, because of the wave height has been decreased, Sediment-Carrying Capacity of water has also been decreased, sediment of out sea will deposit behind submerged dyke, and aggrade the beach flat height. However, few research studies are done upon such a problem home and abroad and even the accomplished results can not be used for real projects. According to these basic function, the paper focuses deep study on the wave decreased function and Siltation Promotion function, which has important values and may be used for real engineering project.Aim at wave decreased function, the paper studies upon the transmission coefficient of submerged dyke through the physical model experiment, four types submerged dyke are studied, research study is on the effect of relative water depth over the dyke to the transmission coefficient of the four different types dyke, and the comparison is done , based on that, the experimental formula is given to the transmission coefficient; According to the Sluice of Submerged Dyke, the paper focus on dyke with Sluice outlet instead of dyke with gap, the sluice and water level of dams area have a close relation to the effect of beach protection and siltation promotion of submerged dyke and structuralstability of dyke, Based on water balance principle and according to tide character, an analytic method was worked out to analyse the changes of water level in different circs, validate the method to different projects shows that the method can simulate water level changes of dams area simply; At present, few research studies are done upon the calculation of Siltation Promotion, especially on silty beach. the paper start with transmission coefficient of submerged dyke, analyse the character of fine sand, set up the forecast method of calculation of Siltation Promotion on silty beach based on the research of mud beach; Finally, according as the nature condition of Yellow River Delta, analyse the character of submerged dyke in project of Beach Protection and Siltation Promotion on Feiyantan beach flat by the theory and method which is found in the paper, a quantitative value of effect will be done as a result.