Study On Failure Mechanism And Simulation Technique Of Beach Protection Structure

With the deeply spreading of channel improvement project in China, the kind of building improved appears more and more. Beach protection structure has become one of the most important improvement measures. As to the channel improvement project that carried out at present, however, the trouble lied in damage and destroy of beach protection structure used is very obvious. This problem could affect the effect of improvement. In addition to the immaturity of solid simulation technique on the failure mechanism, plan layout and structural stability of beach protection structure, studying on its failure mechanism and solving its solid simulation technique problem, therefore, has an important theoretical meaning and practical value.Through outdoor investigations and research, theoretical analysis, generalized model experiment, and directing to side flat kind's beach protection structure that most general used in the Yangtze River's channel improvement, this paper researched in detail the failure mechanism of beach protection structure and fixed the main factors that affected its damage. Selecting X- software platoon as the model of beach protection structure, and two kinds of scale (1:60 and 1:10), the beach protection structure form was systematically simulated from the aspects of geometry similarity, gravity geometry similarity, plan layout similarity and morph similarity, and solve the problem of beach protection structure's simulation technique. Through the experiments of fixed bed and clear water scouring, close to beach protection structure, the article analyzed the water flow structure. Analyzed systematically the situation of beach scouring damage whether there exist beach protection structure's protection, fixed the method of finding scouring range near the beach and had the formula of scour pit through dimensional analysis. By means of stressed experiment on beach protection structure, the paper researched the stressed state near it, analyzed the changing law of pulsation power between the two rubbles.The result of model experiment indicated that the morph characteristic of model on beach protection structure was similar with the original shape, which illustrated that test sand and beach protection structure shape in the experimental model can reflect basically the morph characteristic of original riverbed and beach protection structure.The results of this research could be applied not only to the channel system improvement project directly at the middle and lower course of Yangtze River, but also to that of other river. Moreover, it can enrich the content of channel improvement subject.