白鹤滩水电工程具有窄河谷、大泄量的特点,泄洪消能问题突出。为了避免有限空间内的水舌重叠,采用泄洪表孔3组非对称排布的泄洪消能布置方式。模型试验表明,原布置方案中在坝身泄洪孔口表、深孔单独泄洪时能有效分散水舌,但在坝身表、深孔联合泄洪时,水垫塘内冲击压力峰值超过常规标准,可能影响水垫塘安全运行。通过分析表、深孔水舌的空中碰撞特点,调整表孔俯角后,改善了水舌空中碰撞效果,同时改变深孔平面偏转角后,坦化了大功率泄洪时水垫塘动水冲击压力分布。优化后的非对称布置方案在高效消能的同时保证了水垫塘的安全。

Featured with narrow river valley and large discharge, Baihetan hydropower project is faced with prominent problem of flood discharge energy dissipation. Three groups of asymmetrical surface spillway were adopted to prevent from the overlapping of discharge flow in the limited space. Model tests have shown that in original design scheme, even though the discharge flow disperse effectively with surface or deep hole discharge, the dynamic impact pressure in plunge pool with surface and deep hole combined discharge still exceeds conventional standard, which may affect the safe operation of the plunge pool. In view of this, according to the characteristics of collision of flows from surface spillway and deep orifice, we adjusted the depression angle of the surface spillway to improve the collision effect of water tongues, and meanwhile adjusted the plane deflection angle of the deep orifice to improve the dynamic impact pressure distribution in the plunge pool with high power discharge. The optimized asymmetric arrangement is effective in energy dissipation while ensuring the safe operation of the plunge pool.