Research On Plane Layout For The Approach Channel Of Navigable Constructions In Yinpan Hydro-junction

Yinpan Hydro-junction,which is located in the down stream of Wujiang River , Wulong County. Wujiang has narrow riverbed and flexural plane shape so that it restricts the layout for navigable constructions. It's high peak of flood flow and wide variation range as well as the designed water head influence the navigable condition. These facts bring quite a lot difficulty to the the hydro-junction layout, especially for the navigable constructions to satisfy navigable flow condition of entrance area according to the criterion.The paper is supported by the project"Overall layout for the navigable constructions in the Wujiang River water conservancy hydro-junction project",which belongs to the western traffic construction science and technical project"Research on key techniques in Wujiang River shipping construction". With the hydro-junction hydraulic model and ship model experiment, the layout for the Yinpan hydro-junction navigable constructions, the impact of the entrance area size of the downriver approach channel, the separation wall plane and the structure style to the navigable flow condition, Yinpan hydro-junction scheduling operation method to navigable condition, and its relevant countermeasure were studied. The layout principles are proposed that the Yinpan water conservancy hydro-junction navigable constructions should be laid out concentratively, the ship locks of power station should be laid out on the other bank and on the right concave bank along the river stream. The size of downriver separation navigable wall was optimized. The research indicates that the flow condition is mainly influenced by the length of separation wall.The results of integrative analysis are as follows: when the length of the navigable separation wall L=355m and the bank head is near the top of river bend, the navigable flow condition at the entrance area is relatively better. There are no substantial improvement for the navigable condition to expand the bank head and drill holes through the body of the bank. The highest design navigable flow is turned from 7000m3/s to 9200m3/s after integrative analysis. To satisfy the requirement of the navigable flow condition, the operation scheduling for Yinpan hydro-junction is proposed.