Modeling Study Of Wave Overtopping And Run-up On Landscape Slope Dike And Revetment

With the growing demands of coastal tourism and ocean recreation,landscape slope dikes and revetment with the function of breakwater,landscapes and water touching got great development.The structure of landscape slope dikes and revetment is diff'erent from the conventional one.When waves run over the dikes or up on the top of revetment,the wave overtopping flow,wave run-up flow and secondary generated waves are also different from that with the conventional ones.Wave overtopping flow,wave run-up flow bring serious risk to the buildings,facilities or people on the dike crest and revetment top.Secondary generated waves also affect the berthed ships in waters behind dikes.Therefore,it is necessary to study the wave overtopping and run-up on landscape slope dikes and revetment,evaluate and predict wave overtopping flow,wave run-up flow and secondary generated waves.It is also important for the construction of landscape slope dikes,revetment and the coastal development.Numerical simulation and physical model test methods are respectively used to study the wave overtopping and run-up on the landscape slope dikes and revetment.The main contents are as following:Accuracy and stability improved SPH method(SISPH)is proposed.Firstly,the problems in the simulation of larger amplitude wave propagation for a long time using ordinary SPH method are analyzed.Improvement of smooth kernel function and neighbor particles distribution is proposed for ordinary SPH method,and the accuracy and stability of SPH method are improved.Further,enhanced dynamic boundary condition(EDBC)is established,and then the stability improved SPH(SISPH)method is proposed.The accurate simulation of larger amplitude wave propagation for a long time is realized.Wave overtopping on landscape slope dikes with wide,smooth and impermeable crest,and wave run-up on revetment top with smooth and impermeable surface are studied through physical model test.Regular and irregular waves are used.The whole test is conducted on slope dikes with different superelevation and width of crest or on slope revetment with different superelevation of top.The results of physical test are also studied.Firstly,the relationship of wave overtopping rate and the width of slope dike crest is analyzed,and the reason of overtopping decrease with crest width is explained.The empirical formula of overtopping attenuation coefficient is given.Then,the relationship of wave overtopping flow thickness and the wave overtopping rate at the front of dike crest is studied.The distribution of wave overtopping flow thickness along the dike crest is also discussed.Further,the relationship of secondary generated waves height coefficient and overtopping rate at the end of slope dike crest is studied.The empirical formula of secondary generated waves height coefficient is given using statistical analysis method.The feature of secondary generated waves is also studied using spectral analysis method.Finally,the relationship of wave run-up flow thickness,maximum wave run-up distance on revetment top and the wave overtopping rate at the front edge of revetment top are respectively studied.The distribution of wave run-up flow thickness along the path is analyzed.The empirical formulae of wave run-up flow thickness and maximum wave run-up distance are given.The numerical simulation model of wave overtopping and run-up on landscape slope dikes and revetment is established.In the numerical model,repulsice boundary condition(RBC)is improved.The EDBC and improved RBC are both used in one model.It ensures that the wave propagation,wave overtopping flow and wave run-up flow can be both simulated accurately.Meanwhile,an internal wave generation method which is suitable for SPH method is proposed.This internal wave generation method can absorb the strong nonlinear secondary reflected waves.Based on the established numerical simulation model,the wave overtopping and run-up on landscape slope dikes and revetment is simulated for a long time.The simulated results are compared with physical rmodel test results.These comparisons show that the numerical simulation model established in this paper can simulate the process of wave overtopping and run-up well,it provides a great numerical tool for similar researches.