导流洞出口体形对下游河道影响的试验研究

Experimental Study on the Influence of the Diversion Tunnel Outlet Type to Downstream Channel

结合具体工程的水力学试验,针对导流洞布置集中、导流量大、下游河道流态不易控制等问题,对导流洞出口处体形进行优化研究。通过取消两条导流洞之间的导墙和降低导流洞出口底板高度等措施,使水流能量得到衰减和扩散;适当改变导流洞出口轴线方向,使下游河道主流适当向中心线偏移,减小对下游的冲刷。试验表明,体形优化后,各项水力学指标均明显降低,得到了所需要的理想流态,可保证下游河道以及周围主要水工建筑物的安全。

In light of the specific problems of concentrated diversion tunnel layout,large diversion capacity and difficult to control the downstream flow,the outlet type of diversion tunnel was optimized by hydraulic tests.After removing the guide wall between two tunnels and lowering the outlet floor,the water energy can be attenuated and diffused.By changing the axial direction of diversion tunnel outlet and making the downstream flow moving to the center line,the erosion to downstream channel can be reduced.The experiments show that the hydraulic parameters and flow meet the requirements and the hydraulic structures and downstream channel are safe after the optimization of outlet type.