| Spur dike as a kind of main regulation structure is widely used in channel regulation engineering for converging flow into main channel and controlling the shape of the nature river. When spur dike is built, Some complex flow characteristics such as flow separation, circumfluence appear around spur dikes. When spur dikes built, flow around spur dikes appear three-dimensional turbulent characteristics, under a certain conditions these three-dimensional turbulent characteristics act on spur dikes causing river bed scour and spur dike waterlogging. Twin-groyne as a kind of spur dike arrangement form is widely used in regulation works of mountainous channel. It will be of great importance for the design of channel regulation structure to explore the effect of twin-groyne on flow and studying the flow structure. The work in the thesis is studied combining with the project of Study on water damage mechanism of regulation structure in upper reach of Yangtze River.In this thesis, firstly, we make a brief review and comment for the existing research on the flow structure near spur dike.Then we analyze with investigation and statistics the damage situation of the rapids remediation buildings relying on the channel construction projects in the Xuyu reach of upper reaches of the Yangtze River.With the aid of the method of model experiment and theoretical analysis,we using ADV and water-level gauge collect dates of water-level、flow velocity、turbulent energy、turbulent intensity around twin-groyne. Through drawing comparison chart and coutour map, the distribution disciplinarian of hydraulic characteristics around twin-groyne are discussed in detail. Then we analyze the influence regularity of flow conditions、dam length、select corner、groynehead form、groynespacing on hydraulic characteristics. Through the analysis of flow velocity 、 water-level 、 turbulence characteristics, we find that bend-ended twin-groyne of 120 select corner is the best plane layout. |
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