Mathematical Model Study On Waterway Regulation Of Xiaobaita Beach,Lancang River

Xiaobaita beach, which is closed to Jinghong Hydropower Station, is greatlyeffected by its unsteady discharge and spillway, the dredged channel nearby thedownstream approach channel of Jinghong hub is limited by Baita and Jinghong bridge,more factors influence the waterway regulation, more complex and volatile factorscause the rapids and navigation obstruction and more restrictions to select the dredgedchannel. Therefore, it’s necessary to study regulation measures and rapids genesis ofXiaobaita beach.According to the inland waterway regulation research status, flow mathematicalmodel development and measured terrain hydrological data of Xiao baitabeach,Lancang river, this paper better establishes the average water depth of the finiteelement method of two-dimensional flow mathematical model by simulating complexriver boundary conditions to regulate its channel.The conclusions are as follows:①After the verification of the measured data, the water level, velocity and flowdirection caculated by two-dimensional flow mathematical model are closer to themeasured data. It suggests that two-dimensional flow mathematical model andnumerical methods are reasonable. This method can correctly simulate water flow.②The measuring model based on the complex boundary conditions of disperseddischarge and approach channel with holes established a fomula of distance and flow ifthe flow field of dispersed discharge and full-face discharge are consistent. Thesimulation mode of approach channel cross-flow can better reflect approach channelcross-flow and reflux in entrance area.③According to the analysis of Xiao Baita beach, this paper concludes threeaspects about navigation obstacle factors and beach point:1)The water depth deficiency in part of the downstream approach channel inentrance area;2)The irregular shoreline, the intensive deflecting flow and the strongercross-flow in many places in dredged channel on both sides;3)The beach near the Baitabridge where the flow rate and gradient ratio are over standard during the flood is theflood rapids.④After a multi-program regulation engineering simulation,it proposed themeasures of mouth-cutting, reef blasting, bed sweeping dam construction and so on tosatisfy the navigable basic scale, to improve the flow pattern and shoreline and to settle the rapids.Extendence of approach channel to CK0+580m basically settles the problemof slightly larger cross-flow in entrance area; mouth-cutting and reef blasting improvethe shoreline and flow conditions. All the measures lead to better regulation effect.