窄缝挑坎在丙巷河水库枢纽泄洪隧洞出口的设计应用

Design and use of narrow joint bucket at the flood-releasing tunnel outlet of the Binghanghe Reservoir Control Project

在对丙巷河水库枢纽泄洪隧洞出口进行底流消能、连续式和窄缝式挑坎消能方案的技术经济比较论证后,最终采用窄缝消能方案,但对窄缝消能工目前尚无严密的体形设计方法。在工程设计中,采用大连理工大学刘韩生、倪汉根等人提出的冲击波简化式推导曲线反射扰动线方法,求出满意的对称曲线窄缝挑坎体形,经水力学模型试验验证,效果很好,能较好适应山区狭窄河谷高水头的水库枢纽泄洪消能布置。该消能工的挑射水舌窄而高,水流在空中的紊动、掺气、扩散作用强烈,能消刹大部分动能,射入冲坑后形成三维扩散消能状态,消能率比等宽挑坎高,有效地减轻对下游河床及两侧岸坡的冲刷。

For the flood tunnel outlet of Binghanghe reservoir control project, after the alternatives of the energy dissipations of the bottom current, and the continuous and narrow joint bucket have been compared and discussed based on technical and economic views, the energy dissipation with narrow joint bucket has been adopted finally. However, as for the narrow joint bucket, the design energy dissipator's shape has no certain design method. In this project, we adopted the shock wave simplified formula to introduce the curve reflecting turbulent ray method and gained a satisfied symmetric curve narrow bucket shape. The hydraulic model tests proved that its effectiveness is good, which can meet the requirements of the flood releasing and energy dissipation in the mountainous areas where water head is high. The nappe of the energy dissipator is narrow and high. The water flow in the air forms turbulent fluctuation, aeration, and strong diffusion, which can vanish most of kinetic energy. After entering the injection pit, threedimensional diffusion energy dissipation is formed. The rate of energy dissipation is higher than that of the wide joint bucket, which can effectively decrease the erosion on the downstream bed and the twoside bank slopes.