Study On Flow Characteristics And Impact Scale Of Non-submerged Orthogonal Double Spur Dikes

Spur dike groups are widely used in river management as hydraulic structure. Study on the interaction between spur dikes and river system has a very important and practical significance for scientific layout and construction of spur dikes and river health.In the present work, the research development of single spur dike hydraulics and spur dikes hydraulics is reviewed at the beginning of the paper. The flume tests of non-submerged orthogonal double spur dikes are carried out in the next section, and the backflow length, water distribution and velocity distribution of double spur dikes’function area are analyzed from the three factors-the river dynamic, spur dike length and the storage water level of flume. Though the above research, the conception of spacing threshold value of non-submerged orthogonal double spur dikes is proposed. And spacing threshold value is said by Froude Number Fr, channel width to spur dike length B/b and channel width to water depth B/h by dimensional analysis.In order to cover the shortage of data from flume test, RMA2is used to set up a two-dimension flow numerical model of non-submerged orthogonal double spur dikes. And the mathematical model is calibrated by the data from flume tests. More hydrodynamic simulations are conducted under different conditions, and the change law of spacing threshold of non-submerged orthogonal double spur dikes is obtained, which is indicated by Fr, B/b and B/h. On this basis, multiple linear regression analysis is used to summarize the empirical formula of layout spacing threshold value of non-submerged orthogonal spur dikes. At the end of this paper, artificial neural network (ANN) which has strong nonlinear analysis ability is introduced for the deep data analysis of spacing threshold. And the empirical formula from ANN has higher precision and better generalization than from multiple linear regressions. The researches in this paper have a positive practical significance for the sustainable development and scientific management of river system.