Because of the narrow river channel in a hydropower station dam site,the three-in-one technology,!which combines an emptying tunnel,a flood discharge tunnel with a spiral flow shaft and a diversion tunnel,is used, through which the hydro-junction layout has been optimized.

3-D numerical simulation of flow in shaft spillway with whirling current;

Test and study on volute chamber structural optimization of cyclone shaft;

In virtue of specific head and discharge of Gongboxia hydropower station,the diversion tunnel was studied to reconstruct into flood discharge tunnel with horizontal vertex flow or flood discharge tunnel with vertical vertex flow.