Study On The Wave Characteristics Before The Stepped Seawall

In China, seawalls are generally built to protect coastal areas from storm surges or large waves. With the progress of human society, in order to reduce the impact of large storms on coastal residents living environment,countries have tried to study a variety of new seawall structures to enhance seawall wave dissipation effect and reduce the project cost on the basis of the traditional form of seawall in recent years. Currently, designers have begun to use the stepped seawall to dissipate wave in the coastal areas, but that is still a lack of appropriate research.This paper used a two-dimensional glass flume to establish physical model tests to study the wave dissipation effect of the stepped seawall in the water conservation laboratory of Guangxi University. The test, respectively according to two aspects of slope and height of the steps, designed five test plans, and according to the data of large waves in coastal regions,designed six groups of large incident wave conditions, then tested and calculated each plan of the reflection coefficient, flow field velocity distribution, wave run-up and pressure distribution,etc. It requres comprehensive analyzing and summarizing the influence rules of wave dissipation from the two aspects of the wave form before the stepped seawall embankment.After analysising the test results of every group programs, a conclusion can be given according to researching the rule about the seawall embankment slope and step height impacts on the front wave height, the front embankment velocity,wave run-up on the seawall embankment surface steps and the pulsating pressure seawall embankment on the steps of the plane.This conclusion is that on the one hand, the seawall slope is more slow,the wave height increases before embankment is more obstruct,and the flow rate is decreaser,the wave run-up is also weaker,and the vibration of the seawall is litter, with the seawall step height is constant.In a other word, the more slowly stepped seawall slope, the seawall is more security and stability. On the other hand, when the step height increase, the part of the reflected wave seawall、wave energy of the reflected wave and wave reflection coefficient all will increase, but the wave run-up will reduce, with the seawall step slope is constant.