The Numerical Simulation Of Overtopping Of The Inclined Breakwater With Offshore Submerged-dike

Generally, seawall engineering is a kind of offshore engineering structure which isused to against the impact of the open sea an guarantee the safety behind thebreakwater when the wave with enormous energy coming from the open sea reachesthe offshore areas,it will cause certain impact on the coastal and offshore structure,and under some conditions wave overtopping may be caused which will damage thefarmland, roads and structures behinding the dike and even cause a severe lose of bothlife and property. Building a submerged-dike in front of the seawall will reduce notonly the wave’s impact to the seawall but also the wave overtopping behind theseawall. And the seawall with an offshore submerged-dike are applied in many coastalengineering, especially in soft foundation coastal protection works. The hot issue westudying on is how to chose the section form, the elevation and the top width of thesubmerged-dike and its distance to the main dike so as to make the strucure not onlymeet the demands of safety and stability of the engineering structure itself but alsoreduce the engineering cost and enhance it’s ecomomy at the sametime.Base on the N-S equation,the governing equations discretized by FVM, the VOFmethod is used to track the free surface. Numerical wave flume has been establishedto vertify the effectiveness of the wave generation and absorption. This method hasbeen applied in the numerical simulation of the wave overtopping of the simpleinclined breakwater and the caclulation results are well matched with the cacluationresults which were got from T.savill’s physical model experimental data and theAMAZONE(Hu et al.(2000)) model based on the NLSW equations, which has provedthe validity of the numerical simulation method used in this essay.Through the numerical simulation of the wave overtopping of the inclined breakwaterwith offshore submerged-dike, the essay has got that the secion form, the the elevationand the top width of the submerged-dike and its distance to the main dike all have aremarkable effect on the wave overtopping of the main dike, after analysing the data,the achieved results are as follows:All the following results are under the sameconditions. a) The wave overtopping of the main dikewithout a submerged-dike is much more than that of the one with a submerged-dike; b) The inclined breakwater ismore effective on reducing the wave overtopping than moment breakwater; c) Thehigher the elevation of the breakwater is the less the wave overtopping is; d) Thebreader the top witlth of the breakwater is the less the wave overtoping is; e) Thebreader the top witlth of the breakwater is the less the wave overtoping is; f) Thedistance between the submerged-dike and the main dike has a significant effect on thewave overtopping, Within the wave length as the distance increasing the waveovertopping of the main dike will be increasing first and decreasing latter, whichmeans within a half of the coming wave length,the wave overtopping increases as thedistance increases and between a half to one of the coming wave length, the waveovertopping decreases as the distance increases.